This study comprises a convenient, rapid and very sensitive method for the determination of bovine serum albumin (BSA). The technique is based on fluorescence resonance energy transfer (FRET) between Rhodamine‐6G (R6G) acting as donor and gold nanoparticles (AuNPs) acting as acceptors. This method takes advantage of AuNPs that have high quenching efficiency, therefore the absorption spectra range shifts from 521 to 635 nm when aggregation of the AuNPs takes place. Furthermore, when R6G was electrostatically self‐adsorbed to the citrate‐stabilized AuNPs surface the fluorescence intensity was quenched. After addition of BSA, the fluorescence intensity of the R6G recovered as BSA induced aggregation of the AuNPs and the adsorbed R6G was released to the solution. The recovery of intensity displays a linear relationship with BSA concentration over the range from 0.8 × 10−11 M to 5.6 × 10−11 M. The detection limit for BSA was found to be 4.58 × 10−11 M. The proposed method exhibited rapid analysis with high selectivity for BSA determination in human urine, blood and serum samples.

MnO 2 doped nanostructured zinc oxide was synthesized by solid state reaction route. The prepared material was characterized by X-ray diffraction, scanning electron microscope and UV-Vis absorption spectroscopy. The doping of MnO 2 in ZnÒ enhanced the crystallization and decreased the crystallite size. Surface morphology of the sensing material showed that the hexagonal shaped particles were uniformly distributed in zinc oxide that left large number of pores. These pores acted as humidity adsorption sites. With increase in the concentration of MnO 2 , the pores also increased. The optical band gap of pure ZnO was 4.05 eV. The value of band gap decreased with increase in the MnO 2 doping concentration. The average sensitivity of undoped zinc oxide was 3400 KΩ/%RH. The sensitivity of the sensing element increased with increase in the doping concentration. Sensitivity of MnO 2 doped ZnO composite is more than four times the sensitivity of pure zinc oxide at annealing temperature 600 o C.

No abstract

No abstract