Electrochemical sensing: innovative devices and methodologies for the analyses of drugs of abuse

Chemical sensors are compact, inexpensive and easy-to-use measuring devices that quickly provide the desired analytical response and find application in many fields, such as agriculture, security, industry and others. In this context, my PhD project will focus on the development of electrochemical-type sensors for the identification of the active ingredients present in some of the most common drugs of abuse like cannabinoids, opioids and new psychoactive substances such as synthetic cannabinoids and synthetic opioids. The work will be in collaboration with the Toxicology Laboratory of the Forensic Institute of the Department of Biomedical, Metabolic and Neural Sciences of the University of Modena and Reggio Emilia. In the last decade, the trafficking and use of illicit drugs showed a continuous incremental trend, remaining worldwide a challenging problem for the consequences on society, health, criminality, and environment. Psychotropic effects promoted by drug consumption indirectly affect the population in terms of increasing number of accidents due to reduced driving ability, drug-related crimes and violence, drug-facilitated sexual assaults, spreading of infectious diseases, etc. [1]. Many of the active ingredients of these abuse drugs are electro-active and therefore research and development of electrochemical sensors capable of detecting them can certainly make an important contribution to all organisations working to control and reduce these problems worldwide. Once one or more types of matrices, essentially plant-based or synthetic, have been selected for the determination of the active ingredients, the working methodology will be the one represented in Figure 1. Different electrodic materials will be investigated as the sensing element to promote selectivity and sensitivity. In this regard, carbon-based electrodes, which have proven to be particularly effective for the analysis of cannabinoids, will be initially tested. Then, MIP (Molecular Imprinted Polymers) deposited on quartz crystal microbalances will be explored to combine electrochemical and gravimetric sensing. An additional step of the process will be the use of multivariate analysis methods for the interpretation of the articulated analytical signal that could be obtained when working in complex real matrices. This approach will potentially provide information on both the detection and quantification of the active ingredients under analysis.