Abstract
In this study, we proficiently designed metal nanoparticles embedded in chitosan biopolymeric matrices, which have the ability to be employed simultaneously for the recognition and complete reduction of 4-nitroaniline. Copper nanoparticles embedded chitosan (CuNPs-CH) were coated on glassy carbon electrode to design an efficient electrochemical sensor for 4-nitroaniline. The sensing ability of CuNPs-CH modified electrode toward 4-nitroaniline was assessed by cyclic voltammetry, amperometry and chronoamperometry at working potential of −0.76 V and pH 7.0, while the complete reduction of 4-nitroaniline was analyzed by UV–visible spectrophotometer. The sensing features of CuNPs-CH modified electrode include a sensitivity of −8.166 μA mM−1 cm−2, and detection limit of 0.37 μM. The catalytic ability of CuNPs-CH for 4-nitroaniline reduction reaction was investigated. The results displayed that 4-nitroaniline completely transformed to diaminobenzene in short contact time with a rate constant of 7.51 × 10−3 s−1. The reduction aptitude of CuNPs-CH was also examined toward 4-nitrophenol and rhodamine B; however, the designed system was more efficient toward 4-nitroaniline. The developed approach offered a new methodology for simultaneous detection and reduction of 4-nitroaniline simply for environmental safety purposes.
•Metal nanoparticles embedded chitosan polymeric matrices were prepared via in-situ approach.•CuNPs-CH is highly efficient, inexpensive and easily recoverable catalyst.•High catalytic ability was observed toward 4-nitroaniline reduction.•Electrochemical detection of 4-nitroaniline was achieved with high sensitivity.