Chitosan-gold collapse gel/poly (bromophenol blue) redox-active film. A perspective for selective electrochemical sensing of flutamide.

Chitosan-gold collapse gel (CS-Au CG) was prepared by reducing chloroauric acid (HAuCl) with a polysaccharide, chitosan (CS), in the absence of chemical and physical agents. CS-Au CG was used for the first time as a suitable nano-biocomposite sensing film for efficient one-step electrochemical deposition of poly (bromophenol blue) (PBPB) redox mediator through amino-hydroxyl reaction to prepare a novel anti-androgen drug flutamide (FLU) sensor using glassy carbon electrode (GCE). The effect of electropolymerization cycle, scan rate, pH, and concentration of CS-Au CG/PBPB film on electrochemical behavior of FLU molecules was investigated. The excellent synergetic effect of CS-Au CG/PBPB film showed substantially enhanced electrocatalytic activity for FLU due to the halogen-nitro synthon molecular recognition processes. The selectivity of CS-Au CG/PBPB film sensor for FLU was discussed in detail. The fabricated electrochemical sensor exhibited good linearity in the ranges of 0.01-1245 μM. And also superior sensitivity (0.63 μAμM cm) along with low limit of detection (4.8 nM) was obtained for FLU determination. The CS-Au CG/PBPB film showed an excellent selectivity, good reproducibility, and stability. In addition, the proposed sensor was successfully used to analysis of FLU drug in human urine and human blood serum samples with satisfactory results.