Development of novel impedimetric micro biosensor devices for bioanalysis

Abstract

Recent trends in biosensors highlight the importance of accurate and continuous monitoring newlineof contaminants in food and environment such as chemical compounds, toxins and bacteria. It newlineis also necessary to assess and avoid risks of toxic contaminants in both, human and newlineenvironmental health. The main advantages of the use of biosensors as compared to other newlineconventional methods are; sensitivity, short analysis time, low cost of sample analysis and the newlinepossibility to perform under field condition. Owing to their high sensitivity, selectivity and newlineversatility, affinity-based biosensor devices are attractive for monitoring contaminants in newlinefood and the environment. Affinity biosensors can be classified as labelled and label-free newlinebiosensors. In a labelled biosensor, the target analyte is attached to the enzyme or newlinefluorophores as a label. During the measurement, the electrochemical signal generated by newlinelabel in response to the biosensing process is detected, assuming a direct relation between the newlineconcentration of label and target analyte present. Labels can be biological such as enzyme, newlinechemical materials such as fluorophores and non-chemical materials such as magnetic beads. newlineIn a label-free biosensor, the changes caused by the interaction between target analyte and newlinerecognition element are measured. Label-free biosensors are preferred over labelled ones, newlinebecause of reduction in analysis time and cost. It has also been reported that labeling the newlinetarget analyte changes the binding property which may result in inaccurate measurements. newlineSurface plasmon resonance (SPR) based optical biosensing is also much reported as sensitive newlinelabel-free affinity biosensor, capable of high throughput multi-analyte analysis. However, it newlinehas limitations such as long analysis time, high operational cost and possibility of field newlinedeployment. Whereas, impedimetric biosensors have potential for simple yet rapid detection, newlinelabel-free sensitive analysis, low-cost of detection as well as has potential for field newlinedeployment. Electrochemical impedance spectro