Water Pollutants p-Cresol Detection Based on Au-ZnO Nanoparticles Modified Tapered Optical Fiber

• Published in: IEEE transactions on nanobioscience 2021-07, Vol.20 (3), p.377-384
• Main Authors: Wang, Yu, Zhu, Guo, Li, Muyang, Singh, Ragini, Marques, Carlos, Min, Rui, Kaushik, Brajesh Kumar, Zhang, Bingyuan, Jha, Rajan, Kumar, Santosh
• Format: Magazinearticle
• Language: English
• Subjects: Accuracy; Alanine; Beams (radiation); Biocompatibility; Biosensors; Clinical medicine; Cresol; Cyclodextrin; Cyclodextrins; Electron microscopes; Food industry; Glycine; Gold; gold nanoparticles; L-Alanine; localized surface plasmon resonance; Nanomaterials; Nanoparticles; Nanotechnology; optical fiber biosensor; Optical fiber sensors; Optical fibers; Optimization; p-Cresol; Pollutants; Pollution detection; Probes; Scanning electron microscopy; Selectivity; Sensitivity; Sensors; Tyrosinase; Uric acid; Water pollution; Zinc oxide; zinc oxide nanoparticles; Zinc oxides
• ISSN: 1536-1241; 1558-2639
• DOI: 10.1109/TNB.2021.3082856

In this work, a localized plasmon-based sensor is developed for para-cresol (p-cresol) - a water pollutant detection. A nonadiabatic 40~\mu \text{m} of tapered optical fiber (TOF) has been experimentally fabricated and computationally analyzed using beam propagation method. For optimization of sensor's performance, two probes are proposed, where probe 1 is immobilized with gold nanoparticles (AuNPs) and probe 2 is immobilized with the AuNPs along with zinc oxide nanoparticles (ZnO-NPs). The synthesized metal nanomaterials were characterized by ultraviolet-visible spectrophotometer (UV-vis spectrophotometer) and transmission electron microscope (HR-TEM). The nanomaterials coating on the surface of the sensing probe were characterized by a scanning electron microscope (SEM). Thereafter, to increase the specificity of the sensor, the probes are functionalized with tyrosinase enzyme. Different solutions of p-cresol in the concentration range of 0~\mu \text{M} - 1000~\mu \text{M} are prepared in an artificial urine solution for sensing purposes. Different analytes such as uric acid, \beta -cyclodextrin, L-alanine, and glycine are prepared for selectivity measurement. The linearity range, sensitivity, and limit of detection (LOD) of probe 1 are 0~\mu \text{M} - 700~\mu \text{M} , 7.2 nm/mM (accuracy 0.977), and 59.90~\mu \text{M} , respectively; and for probe 2 are 0~\mu \text{M} - 1000~\mu \text{M} , 5.6 nm/mM (accuracy 0.981), and 57.43~\mu \text{M} , respectively. Thus, the overall performance of probe 2 is quite better due to the inclusion of ZnO-NPs that increase the biocompatibility of sensor probe. The proposed sensor structure has potential applications in the food industry and clinical medicine.