The methods currently being used for the detection and analysis of drugs of abuse such as cocaine, morphine, heroin, etc., are either instrument-based procedures, including chromatograhic (ie. TLC, GC, HPLC) and spectroscopic (IR, MS, NMR) techniques or immunoassay.  The instrumental techniques are usually expensive, not readily amenable to on-site applications, and require pre-treatment and pre-concentration stages before analyte quantification. The immunoassay methods currently used for the analysis of drugs are mainly designed for analysis of urine samples, and include radioimmunoassay (RIA) and enzyme immunoassay (EIA) procedures.  However, RIA involves handling and disposal of radioactive residues.  To make the immunoassay procedure more environmetally friendly, EIA and Fluorescence-labelled immunoassay (FLIA) have been used in place of RIA.  The drawback of EIA and FLIA is that the procedures usually involve separation steps, and often require secondary labelling and the use of secondary reactants.  What is requires is a sensor system that can detect as well as quantify the drug(s) present in a sample in a variety of matrices. There is an urgent need to develop new analytical tools that would be portable, reliable, selective and highly sensitive toward particular analytes. Biosensors are now being developed to meet these requirements.

As part of the Irish Governments 'Initiative on Drugs' the Best Centre research team are deveoping a multi-channel sensor using conducting electroactive poly(aniline) (PANI), in combination with a pulsed potential wave-form to enable selective molecular recognition and provide a unique solution to the detection of drugs of abuse.