Application of Undoped ZnS Nanoparticles for Rapid Detection of E. coli by Fabricating a Mem-Mode Device Sensor After Conjugating Antibody

Zinc sulphide (ZnS) nanoparticles are known for their biological sensors. Conjugation of E. coli bacteria to these ZnS nanosamples are done as well as these bacteria are sensed on dried samples based on memristor-based property. We have varied the concentration of bacteria, and as a result, a variation of current occurs like a hysteresis (Figure eight pattern) loop. ZnS is prepared successfully by the chemical precipitation method. Characterization was done by various techniques to confirm its specifics. In this study, the conjugation of E. coli with the antibody-conjugated nanoparticle is confirmed by taking absorbance before and after adding of E. coli in UV–Vis spectroscopy that results in a significant shift in the wavelength of absorption. Electrical characterization leads to a change in voltage gap among different molar concentration of bacterial conjugated ZnS samples. Results show that process basically leads to a mem-mode observation (either memresistive, memcapacitive or meminductive) in nature. Almost orderly declining pattern of voltage gap with bacterial E. coli concentration is obtained for the as-fabricated devices using ZnS quantum dot in bacterial estimation after conjugating antibody E. coli.