Selective Electrochemical Detection of Explosives with Nanomaterial Based Electrodes

Abstract

Explosive detection technologies play a critical role in maintaining national security, remain an active research field with many devices and analytical/electroanalytical techniques. Analytical chemistry needs for homeland defense against terrorism make it clear that real-time and on-site detection of explosives and chemical warfare agents (CWAs) are in urgent demand. Thus, current detection techniques for explosives have to be improved in terms of sensitivity and selectivity, opening the way to electrochemical devices suitable to obtain the targeted analytical information in a simpler, cheaper and faster way. For the electrochemical determination of energetic substances, a large number of sensor electrodes have been presented in literature using different modification materials, especially displaying higher selectivity with molecularly imprinted polymers (MIPs). MIPs have already been utilized for the detection of hazardous materials due to their mechanical strength, flexibility, long-time storage and low cost. The sensitivity of MIPbased electrosensors can be enhanced by coupling with nanomaterials such as graphene oxide (GOx), carbon nanotubes (CNTs), or nanoparticles (NPs). Specific characteristics of involved nanomaterials, their modification, detection mechanism, and other analytical aspects are discussed in detail. Non-MIP electrosensors are generally functionalized with materials capable of charge transfer, H-bonding or electrostatic interactions with analytes for pre-concentration and electrocatalysis on their surface, whereas nanobio-electrosensors use analyte-selective aptamers having specific sequences of DNA, peptides or proteins to change the potential or current. This review intends to provide a combination of information related to MIPs and nanomaterial-based electrochemical sensors, limited to the most significant and illustrative work recently published.

Colloidal Quantum Dots for Explosive Detection: Trends and Perspectives

“…In this section, we review and discuss the research on CQD-based electrochemical sensors for explosive detection. Good sensitivity, selectivity toward one or more analytes, fast response, repeatability, and accuracy have made electrochemical sensing one of the election techniques for small-molecule detection and, in recent years, it has been gathering growing interest in the field of explosive detection. , In general, electrochemical sensors exploit a redox reaction involving the target analyte at the interface between a conducting solution (electrolyte) and the surface of the working electrode (WE) used as the transduction element. The electron exchange due to the ongoing chemical reactions is responsible for the variation of an electrical signal (current, potential, or capacitance) proportional to the analyte concentration (Figure ).…”

Carbon Electrode Modified with Molecularly Imprinted Polymers for the Development of Electrochemical Sensor: Application to Pharmacy, Food Safety, Environmental Monitoring, and Biomedical Analysis

“…The need to accurately detect analytes in complex matrices in real time is becoming increasingly significant [1]. This requirement spans a wide range of applications, including food safety [2], quality control for drugs and food [3], monitoring environmental air and water pollution [4], biomedical analysis [5], disease diagnosis through monitoring biomarkers in blood or urine [6], combatting food fraud [7], and enhancing civil security [8].…”

Rapid and On-Scene Chemical Identification of Intact Explosives with Portable Near-Infrared Spectroscopy and Multivariate Data Analysis

“…Interesting developments are also being reported in the electrochemical detection of explosives [15][16][17]. Molecularly imprinted polymers are utilized to achieve high selectivity in targeted electrochemical analysis [18]. However, for bulk analysis of unknown energetic materials, a single, non-invasive analysis covering the entire chemical range of explosives is preferred.…”