Surface plasmon resonance-based synthesis of gold nanorods for sensing applications

Gold nanomaterials possess leading interest in the field of nanomaterials due to their vast applications both in advanced chemical and medicinal industries. Gold nanorods (AuNRs) were synthesized via a seed-mediated growth approach for catalytic and electrocatalytic applications. UV–vis absorption spectroscopy and scanning electron microscopy were employed to characterize AuNRs. The focus was to achieve AuNRs of high aspect ratios and good yield. For anisotropic AuNRs, two plasmon peaks are observed; transverse and longitudinal peaks. In the synthesis process, morphology of the gold nanorods was tuned varying the pH of the solution ranges from 3.45 to 1.6. By varying the pH, gold nanorods of different aspect ratios were obtained. Gold nanorods with the aspect ratio of 7.5 containing maximum amount of nitric acid and a pH value of 1.6 revealed the most stability. Catalytic applications were monitored by degradation of an organic pollutant. The degradation percentages of 98% were achieved at 12 min duration. Non-enzymatic electrochemical glucose sensor was fabricated via glassy carbon electrode modification with gold nanorods and studied using cyclic voltammetry. All samples showed good electrochemical response. Among all samples, the one with maximum amount of nitric acid and a pH value of 1.6 revealed the most stability and high sensitivity for glucose sensing. Graphical abstract