# Synthesis of trifunctional indole-imine-based Ag NPs as a molecular probe for selective colorimetric detection of Cd(ii), photo-catalytic and antimicrobial agent

## TL;DR

A new indole-imine compound was used to create multifunctional silver nanoparticles that can detect cadmium, break down pollutants, and kill bacteria.

## Contribution

A novel indole-imine Schiff base was developed for the one-pot synthesis of trifunctional AgNPs with detection, photocatalytic, and antibacterial properties.

## Key findings

- AgNPs-6 detected Cd2+ with a limit of detection of 27.8 nM.
- AgNPs-6 achieved 95% methylene blue degradation under sunlight.
- AgNPs-6 showed enhanced antibacterial activity through silver-ligand synergy.

## Abstract

In the present study, a novel N-(4′-methylphenyl) (4,6-dimethoxy-2,3-diphenyl-1H-indol-7-yl)methanimine 6 (indole imine 6) was synthesized in good yield and was characterized through FT-IR, UV-Vis, GC-MS, 1H/13C NMR, and single crystal XRD techniques. The resulting indole-imine Schiff base serves a dual role as both a reducing and stabilizing agent for the single-pot synthesis of AgNPs-6 in a non-aqueous medium. These AgNPs-6 were then characterized using UV-Vis, FT-IR, Scanning-Electron-Microscopy-Energy-Dispersive-X-Rays (SEM-EDX), Dynamic Light Scattering (DLS), and Zeta Potential measurement. The synthesized AgNPs-6 demonstrated remarkable trifunctionality: it operated as a sensitive colorimetric nano probe for Cd2+ detection (LOD = 27.8 nM), exhibited strong photocatalytic activity with 95% methylene blue degradation under sunlight, and showed enhanced antibacterial performance through synergistic interaction between the silver core and organic ligand. This work establishes a rational design strategy for multifunctional nanomaterials that integrate detection, degradation, and disinfection capabilities within a single platform.

A novel indole-imine Schiff base enabled one-pot synthesis of multifunctional AgNPs, serving as a Cd2+ colorimetric nanoprobe (LOD 27.8 nM), solar photocatalyst (95%), and enhanced antibacterial agent via silver-ligand synergy.