Indigenously synthesized nanocomposite materials: Use of nanocomposite as novel sensing platform for trace detection of Pb2+

Abstract

• Indigenously silane grafted bentonite decorated with Au(NP) is synthesized by greener method. • Novel nanocomposite materials are intended for efficient and selective detection of Pb 2+. • Sensing platform is unaffected with existing co-ions. • High recovery was obtained using real matrix analysis for Pb 2+. Indigenously low-cost, eco-friendly and efficient nanocomposite material Au(NP)/TCODS/BN (trichloro(octadecyl) silane grafted bentonite impregnated with biosynthesized gold nanoparticle) was synthesized. The nanocomposite material was characterized by the SEM/EDAX, TEM and FT-IR analyses. Further, the working electrode was fabricated using the Au(NP)/TCODS/BN material and intended for efficient sensing of Pb 2+ in aqueous media. Electrochemical behaviour of indigenously fabricated electrodes was studied extensively using various electrochemical methods. Cyclic voltammetric results indicated that the nanocomposite fabricated electrode showed a significantly enhanced electroactive surface area. Similarly, the R ct (charge transfer resistance) value is significantly decreased using the nanocomposite material. The differential pulse anodic stripping voltammetry (DPASV) is employed as a sensing method to detect the Pb 2+ and a good calibration line was obtained within the Pb 2+ concentration range (1.00–60.0 µg/L) having the calibration line equation I(µA) = 0.031(µg/L) +0.611(µA) (R 2 = 0.984) at optimized experimental condition. Moreover, the reproducibility tests reveal that the RSD values are obtained below 3%. The estimated LOD and LOQ are 0.81 µg/L and 2.70 µg/L, respectively. The detection of lead is almost unaffected in presence of several co-existing cations and interestingly the real matrix analysis showed that reasonably a good recovery is achieved using Pb 2+ spiked river or spring water samples utilizing the nanocomposite electrode.