The level of free bilirubin is a considerable index for the characterization of jaundice-related diseases. Herein, a biosensor was fabricated via the immobilization of bilirubin oxidase (BOx) on graphene oxide (GO) and polyaniline (PANI) that were electrochemically co-precipitated on indium tin oxide (ITO) conductive glass. The structural enzyme electrode was characterized by FTIR, XRD, and Raman spectroscopy, while the spectral and thermal properties were investigated by UV-vis and thermogravimetric analysis (TGA). Owing to the activity of the fabricated BOx/GO@PANI/ITO biosensor, it could detect free bilirubin with good selectivity and sensitivity in a low response time. The electrochemical response was studied using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). At polarization potential 0.2 V vs. Ag/AgCl, the fabricated sensor illustrated a response in only 2 s at 30 °C and pH 7.5. The LOD and LOQ for the BOx/GO@PANI/ITO biosensor were calculated and found to be 0.15 nM and 2.8 nM, respectively. The electrochemical signal showed a linear response in the concentration range 0.01–250 μM. At 5 °C, the biosensor demonstrated a half-time of 120 days, through which it could be utilized 100 times at this temperature conditions. By using a common colorimetric method, the data on bilirubin levels in serum showed a determination coefficient (R²) of 0.97.

A sulfur nanoparticles-incorporated iron-doped titanium oxide (Fe/TiO₂) with different ratio was successfully synthesized by photolysis method and utilized as effective photoanode in dye sensitized solar cell (DSSC) application with N719 dye. The photolysis method was contained the irradiation of the Fe, S and Ti mixture solution with 15 W source irradiation, and then calcined the formed precipitate. The DSSCs fabricated with Fe/S–TiO₂ photoanode appeared an improved solar-to-electrical energy conversion efficiency of 6.46, which more than pure TiO₂ (3.43) below full sunlight illumination (1.5 G). The impact of Fe content on the total efficiency was also inspected and the Fe content with 6% S–TiO₂ was found 5 wt%. Due to the improved the efficiency of solar cell conversion of Fe/S–TiO₂ nanocomposite, it should be deemed as a potential photoanode for DSSCs with high performance.

A photolysis method was used to prepare a nanocomposite adsorbent (Chitosan-TiO2) and was tested for Cr(VI) removal from aqueous solution. The produce nanocomposite was investigated using, XRD, BET, FTIR, FESEM-EDX and TEM before and after Cr(VI) adsorption. The XRD results shows prepared anatase phase of TiO2 with 12 nm. According to BET measurements, the surface area of the TiO2/chitosan nanocomposite was lower and archived to 26 m2/g, while the TEM and FESEM images show a uniform distribution of TiO2 throughout the chitosan matrix. Adsorption and kinetic experiments were run in batch system under different conditions of pH, contact time, adsorbent dosage and temperature. Experimental Cr(VI) adsorption equilibrium and kinetics data fitted well to Langmuir model. The calculated Langmuir maximum adsorption capacity (qmax) value of nanocomposite was 488 mg/g. Moreover, the highest quantity of Cr(VI) uptake was achieved of pH = 2 and 45℃ and TiO2 and CS-TiO2 had respective removal efficiencies of 94 and 87.5%. The thermodynamic parameters of Cr(VI) adsorption by nanocomposite affirm the spontaneous and endothermic nature of process. Chromium adsorption mechanism by CS-TiO2 nanocomposite were proposed and discussed.