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"Zinc oxide (ZnO) nanoparticles have been investigated in depth, due to their potential as a semiconductor material in dye sensitized solar cell applications. In this current research, ZnO nanostructure was synthesized using a simple precipitation technique with the addition of citric acid (C6H8O7)as the capping agent. Various ratios of ZnO and citric acid were prepared, i.e. 1:1, 2:1, 4:1 and calcination temperatures of 150 and 400°C were used to investigate the effect of those parameters on the ZnO nanostructure and its crystallinity. The nanostructure characteristics, i.e. nanocrystallite size, crystallinity, and optical properties were determined by using x-ray diffraction (XRD), scanning electron microscopy (SEM), and ultra-violet visible (UV-Vis) spectroscopy, respectively. The investigation results showed that ZnO nanostructure was formed as spherical shapes and rods in the range of 19.8–30.8 nm with the lowest band gap energy (Eg) of 3.15 eV obtained under conditions of a 4:1 ratio and calcined at 400°C. Considering nanostructural characteristics, the ZnO nanostructures in this study would be suitable for application as a semiconductor oxide layer in a dye sensitized solar cell."

"Zinc Oxide (ZnO) is an important semiconductor material due to its broad applications, such as in the fields of electronics, optoelectronics, photocatalysts, and solar cells. The main purpose of this work was to investigate the effect of pressure in post-hydrothermal treatment on crystallinity enhancement, crystallite growth, and band gap reduction of ZnO nanoparticles, which could be expected to improve their performance as the semiconductor oxide layer in the dye-sensitized solar cell application. For this purpose, ZnO nanoparticles have been successfully synthesized through the precipitation method, followed by a sequence of thermal treatments including drying, calcination, and Post-hydrothermal Treatment (PHT). For increasing the crystallinity of ZnO nanoparticles, PHT was carried out with a pressure variation of 1 and 3 bar. The resulting nanoparticles were further characterized with X-Ray Diffraction (XRD), Ultra-Violet Visible (UV-Vis) spectroscopy and a Scanning Electron Microscope (SEM). The study showed that by increasing the PHT pressure from 1 to 3 bar caused an adverse effect on the crystallinity, i.e. the crystallite size of ZnO nanoparticles slightly decreased from 27.42 to 26.88 nm. This was expected to be due to the increase of the boiling point of water causing less effective of vapor generated to improve the crystallinity by a cleavage mechanism on the inorganic framework. The band gap energy (Eg), however, was found to increase slightly from 3.25 to 3.26 eV, respectively. Considering the obtained properties, ZnO nanoparticles in this study have the potential to be used as the semiconductor oxide layer in the dye-sensitized solar cells."

"Single phased SrO.6Fe2-xMnx/2Tix/2O3 (x = 0.0; 0.5; and 1.0) nanoparticles, whose mean size was comparable with the crystallite size, were successfully fabricated through mechanical alloying and a subsequent ultrasonic destruction processes. The ultrasonic destruction process employed a transducer operated under amplitudes of 35, 45, and 55 ?m. Results indicated that the mean particle size was not determined by the transducer amplitude, but the mechanical properties of the materials, as well as the initial size of the particles. After ultrasonic destruction, the mean sizes of the particles decreased to the range of 87–194 nm with a narrow distribution width. The mean particle sizes were about 1 to 3 times larger than the respective crystallite sizes. Such fine particles were aimed to decrease the coercivity, as was seen in the sample with x = 0, which showed a decrease in coercivity from 474 kA.m-1 to 24 kA.m-1 and 15 kA.m-1. A further reduction in the coercivity was observed in Mn-Ti substituted strontium hexaferrite."

"Permasalahan distribusi obat yang tidak spesifik pada pemberian obat secara sistemik dalam terapi penyakit kanker dapat diselesaikan dengan sistem pentargetan berbasis nanopartikel. Sehubungan dengan hal tersebut, nanopartikel emas sering menjadi pilihan karena diketahui memiliki aktifitas yang sinergis sebagai anti kanker sekaligus dapat menjadi pembawa dengan karakteristik yang baik dalam memfasilitasi penghantaran obat. Asam folat dapat digunakan sebagai molekul pentarget atas dasar ekspresi reseptor folat yang tinggi pada sel kanker payudara. Penelitin ini dilakukan untuk membuat suatu sistim pentargetan resveratrol (Trans-3, 5, 4-trihidroxy stilbene) yang dikonjugasikan dengan nanopartikel emas sebagai pembawa dan asam folat sebagai molekul pentarget serta menguji efektifitasnya terhadap sel kanker payudara MCF-7. Nanopartikel emas disintesis dengan reaksi reduksi garam emas HAuCl4 dengan pereduksi NaBH4 dan polyvinyl alcohol sebagai penstabil. Asam folat terkonjugasi dengan nanopartikel emas menggunakan 4-Aminothiophenol sebagai linker. Nanokonjugat (FA-AuNp-Rsv) berhasil disintesis dan memiliki karakteristik bentuk yang sferis, dengan ukuran partikel rata-rata 155,0 ±5,42 nm, indeks polidispersitas 0,272 ±0,024 dan zeta potensial -28,01 ±1,82 mV. Uji sitotoksisitas nanokonjugat FA-AuNp-Rsv menghasilkan nilai IC50 sebesar 21,28 ± 1,04 uM, sementara resveratrol bebas memiliki nilai IC50 sebesar 49,94 ± 1,06 uM. Aktifitas anti kanker resveratrol dapat ditingkatkan melalui pembentukan nanokonjugat bersama nanopartikel emas-asam folat dengan karakteristik yang baik dan sesuai untuk pentargetan terhadap sel kanker payudara.

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Nanoparticle technology usualy can solve problems concerning the unspecific distribution of a conventional therapy using anti cancer drugs. Gold nanoparticles often become a choice owing to its synergic activity and ability to fasilitate drug delivery towards cancers. Folic acid on the other hand, can act as a targeting agent based on highly folate receptors expression on breast cancer cells. This research aimed to design a targeting system of resveratrol (Trans-3, 5, 4-trihidroxy stilbene) using gold nanoparticles as a carrier conjugated to folic acid as a targeting agent and test the effectivity against MCF-7 cell line. Gold nanoparticles were synthesized through gold salt HAuCl4 reduction using NaBH4 and polyvinyl alcohol as a stabilizers. Folic acid was conjugated to gold nanoparticles via attachment with 4-aminothiophenol as linker. The resulting nanoconjugate FA-AuNp-Rsv has a sferical shape with size value 155.0 ±5.42 nm, polydispersity index 0.272 ±0.024, and potential zeta on -28.01 ±1.82 mV. Cytotoxic test give an IC50 value of nanoconjugate at 21.28 ± 1.04 uM while that of free resveratol at 49.94 ± 1.06 uM. This result testifies that the anti cancer activity of resveratrol can be improved by forming a nanoconjugate with gold nanoparticles-folic acid that possess a good and suitable characteristics  as a targeting system against breast cancer."

"Ketahanan bahan bakar pada temperatur rendah menjadi salah satu faktor penentu kualitas bahan bakar B30. Pada temperatur lingkungan yang mendekati titik kabut bahan bakar, presipitasi dan kristalisasi B30 sangat rentan terjadi sehingga menjadi salah satu permasalahan utama dalam implementasi penggunaan biodiesel sebagai bahan bakar campuran minyak solar. Penelitian ini menyajikan optimasi cold-flow improver (CFI), berbasis alumina nanopartikel dan sorbitan monooleat, untuk memperbaiki sifat bahan bakar B30 pada temperatur rendah. Alumina nanopartikel disiapkan dengan sintesis terkontrol sehingga menghasilkan γ-Al2O3 Nanorods. Pengaruh γ-Al2O3 nanopartikel dan sorbitan monooleat (SMO) dianalisis terhadap cold-flow properties B30 meliputi titik kabut, cold filter plugging point, filter blocking tendency, dan presipitasi. Penggunaan surfaktan-nanopartikel tersebut menghasilkan pengaruh yang signifikan terhadap perbaikan cold-flow properties B30 berdasarkan analisis varians (ANOVA). Formula yang terdiri atas 50 ppm γ-Al2O3 nanopartikel dengan 0,1 %-b/v SMO merupakan kondisi optimum CFI untuk B30 yang ditentukan berdasarkan response surface methods. Penggunaan SMO (0,1 %-b/v) menghasilkan stabilisasi γ-Al2O3 nanopartikel dalam B30 dengan penghambatan sedimentasi partikel berukuran > 4 mikron hingga 82%. CFI berbasis γ-Al2O3 nanopartikel dan sorbitan monooleat menghasilkan efek sinergis dalam menghambat pembentukan kristalisasi pada bahan bakar sehingga menjadi salah satu kandidat aditif CFI untuk B30.

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Poor cold-flow properties of biodiesel blends as B30 is a main problems that hinders the implementation of biofuel. This study presents the optimization of cold-flow improver (CFI) for improving fluidity of B30 at low-temperature based on a new class of combination between sorbitan monooleate (SMO), a non-ionic surfactant, and γ-Al2O3 nanoparticles, which was prepared via ultrasonic sonochemistry. Both of CFIs were studied on cold-flow properties of B30, i.e., cloud point, cold filter plugging point, filter blocking tendency, and precipitate, using response surface methods. Based on the results, the cold-flow improver formulation achieved at the following condition where the concentration of SMO is 0,1%-w/v, and the concentration of alumina nanoparticles is 50 ppm, respectively. The results showed that it is possible to predict the four response parameters using models generated by response surface methods since the experimental values were found to be in good agreement with the predicted values (accuracy > 97,5%). SMO showed increasing stabilization of γ-Al2O3 nanoparticles in B30 by 82% inhibiting sedimentation of particles > 4 microns. The use of γ-Al2O3 nanoparticles and SMO produces a synergistic effect for the inhibition of excessive crystallization wax at low-temperature so that it becomes one of the candidates for additives in B30 biodiesel blend."

"Konsumsi air yang bersih dan sehat adalah kebutuhan setiap mahluk hidup. Menurut WHO, konsentrasi ion kromium VI yang lebih dari 50 ppb dalam air minum dapat membahayakan kesehatan manusia WHO 1993 . Untuk itu perlu suatu metode penentuan konsentrasi ion kromium VI dalam suatu sampel dengan mudah, murah, cepat dan mobile. Pada penelitian ini elektroda glassy karbon yang kurang elektroaktif terhadap spesi kromium VI dan Kromium III, dimodifikasi dengan komposit grafena-nanopartikel Au yang dielektrodeposisi secara simultan dengan teknik cyclic voltammetry CV pada permukaan elektroda glassy karbon untuk meningkatkan sensitifitasnya, untuk kemudian digunakan dalam analisis spesiasi ion logam kromium VI dengan teknik square wave siklik voltmmetry SWSV dan Linear Scan Voltammety LSV dan penetuan kromium III dengan teknik cyclic voltammetry. Elektroda glassy karbon termodifikasi dikarakterisasi dengan Scanning Electron Microscopy SEM, Fourier Transform Infrared Spectroscopy FTIR, X-Ray Diffraktofotometry XRD dan persamaan Randless-Sevcik. Konduktifitas yang tinggi dan luas permukaan yang besar pada grafena, menjadikan grafena menjadi tempat fiksasi/pertumbuhan nanopartikel Au yang bersifat elektrokatalisis terhadap logam kromium, dan memiliki konstribusi yang besar dalam meningkatkan sinyal arus listrik/sensitifitas pada analisis spesiasi ion logam Cr VI dan Cr III dengan teknik SWSV dan LSV pada rentang linear 0,01 ppm hingga 0,35 ppm dengan nilai limit deteksi LoD 48,7 ppb, dan untuk penentuan Cr III dengan teknik CV pada rentang linear 0,01 ppm hingga 0,35 ppm dengan nilai LoD 33,81 ppb dan LoQ 112,70 ppm. Elektroda kemudian digunakan untuk mendeteksi ion logam Cr VI dalam air danau di lingkungan universitas Indonesia dan didapatkan kadar sebesar 74,33 ppb dan hasilnya dibandingkan dengan metode pembentukan kompleks Cr-Difenil Karbazon yang ditentukan secara UV-Vis spectrofotometri dengan perbedaan hasil sebesar 30,88.

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The consumption of clean and healthy water is the necessity of every living being. According to WHO, the concentration of more than 50 ppb of chromium VI ions in drinking water can harmfull for human health. So, we need a method of determining the concentration of chromium ion VI in a simple way, easy, cheap, fast and mobile. In this study, an electroactive glassy carbon electrode modified with graphene and Au Nanoparticles composites, for quantification to chromium VI and Chromium III species, are simultaneously electrodeposited with cyclic voltammetry CV techniques on the surface of glassy carbon electrodes to increase their sensitivity, and then used in the speciation analysis of the of chromium metal ions VI with square wave cyclic voltammetry SWSV and Linear Scan Voltammety LSV and for chromium III determined by cyclic voltammetry technique.

The modified glassy carbon electrode is characterized by Scanning Electron Microscopy SEM, Fourier Transform Infrared Spectroscopy FTIR, X Ray Diffractofotometry XRD and Randless Sevcik equations. The high conductivity and large surface area of the graphene make the graphene as fixation site for an electrocatalytic gold nanoparticles growth, and has a large contribution for improving electrical current signals sensitivity in speciation analysis of Cr VI and Cr III with SWSV and LSV technique with linear range at 0.01 ppm to 0.35 ppm and detection limit LoD of 48.7 ppb, and for determination of Cr III with CV technique with linear range from 0.01 ppm to 0.35 ppm with value of LoD is 33.81 ppb and value of LoQ is 112.70 ppm. The modified electrode then used to detect Cr VI metal ions in lake water in Universitas Indonesia and obtained a concentration of Chromium VI is 74.33 ppb and the results were compared with formation of Cr diphenyl carbazon complex method by UV Vis spectrophotometry with yield difference of 30, 88 ."

"Pengembangan biosensor dengan kombinasi DNA aptamer dari penislin G dan nanopartikel emas (AuNP) digunakan untuk mendeteksi penisilin G. Kondisi optimum aptasensor diperoleh dengan konsentrasi NaCl dan aptamer masing-masing 0,25 M dan 2 μM. Uji sensitifitas menunjukkan nilai limit deteksi aptasensor penisilin G sebesar 1 mg/L dan mampu mendeteksi penislin G dalam kisaran 1-27 mg/L. Aptasensor penisilin G menujukkan hasil yang spesifik dalam mendeteksi penisilin G setelah dilakukan uji dengan beberapa antibiotik; ampisilin, kanamisin, kloramfenikol dan eritromisin. Hasil mutasi iradiasi ultaviolet dan iradiasi gamma terhadap P.chrysogenum tipe liar menunjukkan peningkatan produksi pensilin G secara signifikan. Melalui metode deteksi aptasensor menunjukkan bahwa penisilin G dari strain P. chrysogenum tipe liar, mutan (iradiasi ultraviolet), mutan (iradiasi gamma), serta mutan (iradiasi ultraviolet dan iradiasi gamma) masing-masing menunjukkan konsentrasi deteksi sebesar 9,75 ± 0,004; 25,25 ± 0,005; 37,5 ± 0,005; dan 45 ± 0,004 mg/L.

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The development of biosensors with a combination of aptamer DNA from penislin G and gold nanoparticles (AuNP) was used to detect penicillin G. The optimum condition of aptasensor was obtained with NaCl and aptamer concentrations of 0.25 M and 2 μM, respectively. The sensitivity test showed the aptasensor penicillin G detection limit value of 1 mg/L and was able to detect penicline G in the range 1-27 mg/L. Aptasensor penicillin G shows specific results in detecting penicillin G after testing with several antibiotics ampicillin, kanamycin, chloramphenicol and erythromycin. The results of ultaviolet irradiation and gamma irradiation on wild-type P. chrysogenum showed a significant increase in production of penicillin G. Through aptasensor detection method showed that penicillin G from strains of wild type P. chrysogenum, mutants (ultraviolet irradiation), mutants (gamma irradiation), and mutants (ultraviolet irradiation and gamma irradiation) showed detection concentrations of 9.75 ± 0.004; 25.25 ± 0.005; 37.5 ± 0.005; and 45 ± 0.004 mg / L, respectively."

"Nanopartikel emas (AuNPs) memiliki keunggulan berupa luas permukaan yang besar sehingga banyak digunakan sebagai sensor. Boron-doped diamond (BDD) adalah salah satu elektroda dengan sifat superior seperti jendela potensial lebar, arus latar belakang yang rendah, inert, dan stabil. Pada penelitian ini, modifikasi permukaan BDD dengan nanopartikel emas dilakukan untuk meningkatkan konduktivitas dan sensitivitas elektroda BDD untuk aplikasi sebagai sensor oksigen. Sintesis AuNPs dilakukan dengan  menggunakan capping agent alil merkaptan yang cocok dengan Au berdasarkan sifat hard-soft acid base. Karakterisasi AuNPs dengan menggunakan spektrofotometer UV-Vis spektrofotometer UV-Vis menunjukkan panjang gelombang spesifik nanopartikel emas di sekitar 510-580 nm, sedangkan karakterisasi TEM dan PSA menunjukkan ukuran AuNPs rata-rata adalah 11±4 nm. AuNPs yang disintesis kemudian dimodifikasikan pada permukaan BDD dengan menggunakan metode perendaman di bawah radiasi UV. BDD termodifikasi AuNPs (AuNPs-BDD) yang terbentuk dikarakterisasi dengan X-ray photoelectron spectroscopy (XPS) dan scanning electron microscopy (SEM-EDS). Studi pendahuluan untuk penentuan sensor oksigen (DO) dilakukan dengan menggunakan teknik cyclic voltammetry (CV). Sementara itu, aplikasi AuNPs-BDD sebagai sensor oksigen untuk penentuan biochemical oxygen demand (BOD) dilakukan dengan menggunakan teknik amperometri. Hasil pengukuran menunjukkan bahwa sensor yang dibuat memiliki kemampuan sebanding dengan elektroda emas dan memiliki performa yang cukup baik sebagai sensor oksigen dengan nilai S/B, LOD DO, dan LOD BOD berturut-turut sebesar 4,01, 0,085 ppm, dan 0,055 ppm.

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Gold nanoparticles (AuNPs) have an advantage in terms of surface area and are widely used as sensors. Boron-doped diamond electrode (BDD) is one of the electrodes with superior properties such as a wide potential window, low background current, inert, and stable. In this work, modification with gold nanoparticles was carried out to increase the conductivity and sensitivity of BDD electrode for application as oxygen sensors. The synthesize of AuNPs was performed using allyl mercaptan as the capping agent, which suitable for Au based on its hard-soft acid properties. Characterization by using UV-Vis spectrophotometer showed that AuNPs was successfully synthesized due to the specific gold nanoparticles wavelength at around 510-580 nm, while TEM and PSA characterization showed that the average of AuNPs size was 11±4 nm. The synthesized AuNPs was then employed to modify the BDD surface by immersion method under UV irradiation. The preliminary study of determining the oxygen (DO) sensor was carried out using the cyclic voltammetry (CV) technique. Meanwhile, the application of AuNPs-BDD as an oxygen sensor for the determination of biochemical oxygen demand (BOD) was carried out using amperometric technique. The result showed that the sensor was comparable to gold electrode and had a good performance as oxygen sensors with the S/B, LOD DO, and LOD BOD value were 4.01, 0.085 ppm, and 0.055 ppm respectively."

"Nanopartikel (NP) Mangan ferit (MnFe2O4) telah menyediakan platform serbaguna untuk mengembangkan sistem nano multifungsi untuk Magnetic Resonance Imaging (MRI) dan modalitas Single Photon Emmision Computed Tomography (SPECT). Di sini, kami mengembangkan NP Yodium-131 (131I)-bertanda nimotuzumab-MnFe2O4 baru sebagai MRI multimodalitas dan SPECT untuk diagnosis penyakit seperti kanker. Sintesis NP MnFe2O4 dilakukan dengan menggunakan ekstrak Piper nigrum (EPN). EPN berperan sebagai bahan sumber basa lemah dan zat penstabil yang menunjukkan adanya alkaloid, polifenol, serta terpenoid yang dikonfirmasi dari uji fitokimia. NP MnFe2O4 kemudian dikonjugasikan ke Epidermal Growth Factor Receptor (EGFR) nimotuzumab melalui PEG-linker heterobifungsional. Radiolabeling NP MnFe2O4 terkonjugasi nimotuzumab dengan Yodium-131 dilakukan dengan metode oksidasi iodobead. NP MnFe2O4 hasil sintesis dikarakterisasi dengan DRS, FTIR, XRD, SEM, TEM, dan EDX. NP MnFe2O4 yang dikonfirmasi memiliki bentuk bulat, dengan ukuran rata-rata sekitar 21 nm dengan bentuk kristal kubik fase tunggal. Nanopartikel menunjukkan sifat magnetisasi 23,4 emu/g sebagaimana dikonfirmasi oleh analisis VSM. Hasil konjugasi MnFe2O4 -nimotuzumab berhasil dilakukan dengan linker SH-PEG-NHS. Nanopartikel 131I-bertanda nimotuzumab-MnFe2O4 ​​yang disiapkan memberikan kemurnian radiokimia yang sangat baik sebesar 93,57 ± 0,52%. Investigasi biologis di masa depan dari NP MnFe2O4-nimotuzumab-131I baru ini sebagai nanoprobe MRI dan SPECT baik in vitro dan in vivo masih diperlukan

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Manganese ferrite (MnFe2O4) nanoparticles (NPs) has provided versatile platform to develop multifunctional nanosystem for magnetic resonance imaging (MRI) and single-photon emission computed tomography (SPECT) modalities. Herein, we develop novel iodine-131-labeled-nimotuzumab-MnFe2O4 NPs as multimodalities MRI and SPECT nanoprobe for diagnosis of disease such as cancer. The synthesis of MnFe2O4 NPs were done using Piper nigrum extract (PNE). PNE plays role as a weak base source material and stabilizing agent which showed the presence of alkaloids, polyphenols, as well as terpenoids as confirmed from the phytochemical test. MnFe2O4 NPs were then conjugated to anti-epidermal growth factor receptor (EGFR) nimotuzumab via heterobifunctional PEG-linker. The radiolabeling of nimotuzumab-conjugated MnFe2O4 NPs with iodine-131 was performed using iodobead oxidizing method. The synthesized MnFe2O4 NPs were characterized by DRS, FTIR, XRD, XRD, SEM, TEM, and EDX. The confirmed MnFe2O4 NPs have a spherical shape, with an average size of about 21 nm with a single-phase cubic crystal form. The NPs showed magnetization properties of 23.4 emu/g as confirmed by VSM analysis. The results of the conjugation of MnFe2O4-nimotuzumab were successfully carried out with the SH-PEG-NHS linker. The prepared iodine-131-labeled-nimotuzumab-MnFe2O4 NPs gave an excellent radiochemical purity of 93.57 ± 0.52 %. Future biological investigations of this novel iodine-131-labeled-nimotuzumab-MnFe2O4 NPs as MRI and SPECT nanoprobe both in vitro and in vivo are required. "

"Tesis ini membahas tentang fabrikasi dan pengujian sel surya berbasis sintesa larutan (DSSC) dengan bahan utama ZnO sebagai elektroda dan struktur tandem sebagai struktur utamanya. Bahan ZnO digunakan karena mudah didapatkan dan sifat fisisnya serta energinya memiliki kemiripan dengan bahan bandgap lebar yang sudah lebih dulu digunakan, seperti TiO2, dengan mobilitas elektron yang lebih tinggi. Penulis telah berhasil membuat sampel DSSC berbahan ZnO dengan struktur tandem. Berdasarkan pengujian, tampak bahwa struktur tandem memiliki potensi untuk meningkatkan tegangan keluaran hingga 90%, namun salah satu kendala yang terjadi adalah menjaga kestabilan nilai arus kedua tumpukan DSSC agar nilai arus keluaran struktur tandem tidak mengalami penurunan.

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This tesis describes about fabrication and measurement of DSSC with ZnO as main cathode material and tandem as main structure. ZnO is used because it is easy to be found and its physical and energy characteristics are similar to TiO2 with higher electron mobility. ZnO-based DSSC with tandem structure sample has been made. From the test, it can be seen that tandem structure is able to increase output voltage up to 90%, but one of threat that need to be concerned is the stability of current value for each single DSSC, so that the output current of tandem DSSC won’t be decreased."