Enhanced fluorescence response and effective petroleum sensing performance of silver/copper nanocomposites

Creation of high-performance petroleum sensors based on the fluorescent plasmonic nanostructures with tailored physiochemical properties remains challenging. Based on this idea, pulse laser ablation in liquid (PLAL) approach at optimum laser fluence (14.2 ± 3.9 J cm⁻²) was used to make three samples (in deionized water) including silver nanoparticles (AgNPs), copper nanoparticles (CuNPs) and their nanocomposites (AgCuNCs). The structure, morphology, absorption, fluorescence (FL), color purity and petroleum sensing potency of these samples were determined via thorough characterizations. TEM images of each colloidal sample verified their strong nanocrystallnity with preferred lattice planer growth and uniform dispersion. The mean diameter and fluorescence quantum yield of AgCuNCs were correspondingly 7.4 ± 1.21 nm and 0.072. In addition, the obtained nanocomposites (NCs) showed prominent photoluminescence, localized surface plasmon resonance absorption and fluorescence decay lifetime of 3.5 ± 0.12 ns. Fiber-optic sensors were designed by coating each sample (acted as sensing elements) on the optical fiber and their sensing capacities were tested against N95 and N97 petroleum. The AgCuNCs-coated fiber-optic sensor displayed better petroleum sensing capacity than those designed with pure AgNPs and CuNPs coating. It is asserted that the proposed stable colloidal NCs with excellent physicochemical characteristics may contribute towards the development of cost-effective and eco-friendly fiber-optic sensors desirable for petroleum detection.