Glutathione-Assisted Synthesis of Hierarchical PbS Via Hydrothermal Degradation and Its Application in the Pesticidal Biosensing

Thiol biomolecule of glutathione (GSH) combined with lead ion as precursor for synthesis of hierarchical PbS via hydrothermal degradation has been developed. The precursor and as-prepared PbS were characterized by Fourier-transform infrared spectra (FTIR), X-ray diffraction (XRD), scanning electronic microscopy (SEM) and electrochemical technique. Flower-shaped micron crystals, submicron-sized spherical particles and dendritic PbS were controllably synthesized by adjusting pH value of the precursor solutions. GSH acted as both soft template and sulfur source in the synthesis. To investigate the suitability of PbS for pesticidal sensing application, an pesticidal biosensor based on the AChE-CHIT/dendritic PbS/GCE has been devised. Organophosphate pesticide dimethoate was selected as model to examine the feasibility of pesticidal bio-sensing. Under the optimum conditions, a quantitative measurement of dimethoate was achieved with the linear range of 0.05 μM to 1.0 μM and the detection limit of 0.02 μM.