gain-assisted transition metal ternary nitrides (ti1−xzrxn) core–shell based sensing of waterborne bacteria in drinking water

We propose gain-assisted ti1 − xzrxn-based multilayered core–shell nanoparticles (mcsnps) as refractive index (ri) sensor for real-time and label-free detection of waterborne bacteria. ri sensor designs optimized for diseases caused by pathogen escherichia coli (e. coli), serratia marcescens (s. marcescens), and mierococcus lysodeikticus (m. lysodeikticus) are presented. mie theory–based analysis shows that the precise incorporation of optical gain can compensate plasmonic losses at resonant wavelength and enhance sensor’s figure of merit (fom) for bacteria detection up to ~ 106–107. the use of ti1 − xzrxn ternary alloy as plasmonic material is advantageous as (i) ti1 − xzrxn offers an alternative to the conventional plasmonic materials (e.g., au, ag, cu, etc.); (ii) specific ti/zr fractions in ternary ti1 − xzrxn reduces the critical gain requirement compared to binary tin; and (iii) spectrum can be fine-tuned by controlling ti/zr fraction. the present work can led to the development of ultrasensitive plasmonic sensors capable of single bacteria detection as well as level of concentration of bacteria in water.