Electrochemical Detection of Analytes in Fluids
Authors: Arya Sandeep , Khosla Ajit 
Published: May 2020

A sufficient intake of nutrients is essential to remain healthy and hence few accurate methods of analysis for these nutritional values in pharmaceutical, fruits, milk, energy drinks, etc. are required. A wide variety of analytical techniques, such as Thermogravimetry, Spectrophotometry, High performance Liquid Chromatography (HPLC), HPLC coupled with Mass Spectroscopy, Colorimetric, Flow Injection Chemiluminescence, Fluorimetric and Electrophoresis, etc. have been reported for the quantification of such nutrients. However, some of these methods are inappropriate for standard analysis as these techniques employed under these methods are complicated analytical processes, time-consuming and involve expensive instrumentation. Therefore, it is essential to develop a simple method to monitor the nutritional values over a wide range. Among various analytical methods, electroanalytical technique is a potential alternative due to fast, simple, and low-cost detection capabilities, making them ideal for applications in the field of pharmacy, food, and agriculture. Also, due to the possibility of miniaturization, this analytical technique gained much attraction. There has been a consistent effort towards the development of novel sensing strategies with specific attention to enhance specificity, sensitivity, and response time. In recent years, electrochemical methods are applied widely to detect and determine a variety of biological compounds, organic molecules and inorganic ions. Among various electroanalytical methods, cyclic voltammetry, differential pulse voltammetry, chronoamperometry, chronocoulometry, linear sweep voltammetry, square wave voltammetry and adsorptive stripping voltammetry are commonly employed for the detection of analytes. There are few selected nanomaterials that are being used as base materials in emerging technologies for possessing exceptional potential. Among such materials, tin oxide (SnO2) is a material with exciting sensing properties such as high sensitivity, good chemical stability, high electron mobility, fast response, and good recovery speed. It is a key functional material that has been used extensively in transparent conductors, transistors, optoelectronic devices and electrochemical modifiers on electrodes. Electrochemical analysis using SnO2 nanomaterial has been used for the qualitative and quantitative determination of amount of electro active analytes. This method is reported to be highly accurate, reliable and cheap.

During the last few years, we began to focus on synthesizing and developing SnO2 nanomaterials for the detection of different analytes in fluids. My team is currently working for the detection of different analytes like Folic acid, Riboflavin and Vitamin B12, etc. in fluids and pharmaceutical samples. It is observed that all these analytes can be detected using certain modifications in sensing (SnO2 nanomaterials) electrodes. The sensing characteristics of SnO2 can further be improved by chemical doping with appropriate elements. The advantage of this method is that the detection is possible multiple times using same sensing electrode. As per our experience, SnO2 has great potential to become an economical sensing electrode and can be synthesized on any conducting substrates. This talk will discuss examples of ongoing research work on different SnO2 based sensors.

Figure 1