Triazole thiazole 4-Nitrobenzohydrazide Schiff base-stabilized silver nanoparticles for selective and efficient detection of neomycin

The widespread usage of antibiotics is leading to an increased negative impact on living organisms due to the consumption of polluted water containing drug residues. The emergence of drug-resistant bacteria has additionally manifested a growing need to identify commonly available medications in water sources. A rapid colorimetric nanosensor is developed in this study to selectively detect Neomycin, an antibiotic of class aminoglycosides. A straightforward reduction method was employed for the formation of Schiff base (4-nitrobenzohydrazide triazole thiazole) capped silver nanoparticles (4NHTS-AgNPs). Upon treatment with Neomycin, the colloidal solution of 4NHTS-AgNPs exhibited an immediate color change from yellow to red while no visible change was observed by addition of other competitive drugs. With an increase in drug concentration, the plasmonic characteristic peak of 4NHTS-AgNPs at 405 nm exhibited a progressive reduction. Furthermore, incubation with NeO resulted in a bathochromic shift and broadening to longer wavelength, specifically to 565 nm. The combined quenching and shift of the plasmonic peak were attributed to the aggregation of 4NHTS-AgNPs induced by the NeO through hydrogen bonding. The 4NHTS-AgNPs based sensor demonstrated a linear dynamic range of 0.02–100 μM, with a limit of detection and limit of quantification of 0.0061 μM and 0.020 μM, respectively. Even in the presence of interfering drugs and for real sample analysis, the selectivity of 4NHTS-AgNPs based sensor towards neomycin remained consistent.