Ultraviolet-Printing-Assisted Surface-Confined Growth of Silver Nanoparticles on Flexible Polymer Films for Cu²⁺ and H₂S Sensing

Abstract

Metal nanoparticles (NPs) confined on the surface of flexible polymers films are highly sought after for a diverse range of applications. Herein, we report a facile substrate-independent strategy for surface-confined growth of silver NPs (AgNPs) on the surfaces of chemically diverse flexible polymer film substrates represented by polypropylene (PP), polyvinyl chloride (PVC), and polyethylene terephthalate (PET). The surfaces of polymer films were subjected to ultraviolet-printing and conjugated to the hyperbranched polyethyleneimine (PEI). The PEI-functionalized surfaces were subjected to surface-confined growth of AgNPs via three approaches. Besides PEI, the ability of quaternary amine and carboxylic acid functional groups to assist surface-confined growth of AgNPs is also evaluated. All the films with surface-confined AgNPs exhibited absorbance due to the surface plasmon resonance (SPR) characteristic of AgNPs. The AgNPs confined on the surface of PP films were functionalized with 4-mercaptobenzoic acid, and the λ max for SPR absorbance of the resulting platform was found to exhibit a markedly higher bathochromic shift when exposed to Cu 2+ ions. This Cu 2+ ions sensor could sense Cu 2+ ions with a limit of detection of 2.6 ppm. Besides Cu 2+ sensing via a bathochromic shift in λ max for SPR absorbance, the SPR absorbance of AgNPs confined on the surface of PP films was found to diminish upon exposure to the aqueous solution of sodium hydrosulfide (NaSH), which acts as a hydrogen sulfide (H 2 S) donor. The intensity of the SPR absorbance was found to decrease >40% upon exposure to 5 μM aqueous NaSH solution, whereas the SPR signal almost completely disappeared with visual decoloration when the films were exposed to 50 μM aqueous NaSH solution. This highlights the H 2 S sensing ability of the AgNPs confined on the surface of PP films. In brief, this study is a step toward the future development of flexible chemical sensor platforms and beyond.

Silver Nanoparticle-Incorporated Defect-Engineered Zr-based Metal–Organic Framework for Efficient Multicomponent Catalytic Reactions

“…Silver nanoparticles (Ag NPs) have been recognized as a wondrous material by the scholar community on account of their impressive extent of applications in catalysis, − sensing, − optoelectronics, etc. These emanate from their unique properties such as surface plasmon resonance, photoluminescence, and antimicrobial activities, to name a few.…”