| Popis: |
Nanosensors have been proven to be a powerful tool in sensing various targeting analytes such as proteins, DNA, and RNA and small molecules such as toxins, drugs, metabolites, biomarkers, and environmental pollutants with high specificity and selectivity. Among various environmental pollutants, pollution by contamination of heavy metal is one of the most serious issues in current global scenario because of its potential toxicity toward human and aquatic life. Conventional methods of detecting such toxic ions include inductively coupled plasma mass spectroscopy (ICP-MS) and atomic absorption spectroscopy (AAS). These methods are accurate in minute-level detection, but still possess some drawbacks such as high time consumption, involvement of toxic chemicals, and requirement of sophisticated laboratory setup. Therefore, there is a need for inexpensive, user-friendly, quick, and portable methods for detection of these toxic ions. Efforts are being made in developing gold nanosensors for easy monitoring of heavy metal toxins in environmental samples. Due to unique optical, electrical, and mechanical properties, gold nanoparticles render improved performance as sensor probe for better sensitivity, selectivity, portability, and multi-load detection capability. During sensing process, the nanoparticles aggregate in the presence of specific metal ions and show visible color change from red to blue to colorless. The qualitative color change detected using naked eyes shows the presence of targeted heavy metal ions. Apart from the qualitative analysis, the quantitative estimation can be achieved with the help of gold nanoparticles by various techniques such as CCD or CMOS sensors, photodetectors, and color light sensors. This chapter deals with various synthesis processes, potential colorimetric-based sensing applications of gold-based nanosensor, and associated electronic circuitry, which could be employed for detection and quantification of various heavy metal toxins. |
