Transferrin Analysis in Wistar Rats Plasma: Towards an Electrochemical Point-of-care Approach for the Screening of Alcohol Abuse

Simple and low-cost point-of-care testing (POCT) approaches are necessary not only for the diagnosis of alcohol abuse but also for the follow-up of patients during the treatment of alcohol dependence. To advance the development towards these approaches, a disposable screen printed-based electrochemical sensor is proposed for the diagnosis of chronic alcohol abuse. The selected biomarker to be screened (and followed up) was the carbohydrate deficient transferrin (CDT), which was assessed using the parameter "Electrochemical index of glycosylation " (EIG). EIG is defined as the ratio between the signal generated by carbohydrates present in transferrin (Tf) (selectively labeled with an Os(VI) tag) and the signal generated by the electroactive amino acids present in Tf, measured by adsorptive transfer square wave voltammetry (AdTSWV). The electrochemical sensor exhibited a good limit of detection (LOD <= 0.7 g L-1) well below the normal range of transferrin in serum (ranging from 2 to 3.6 g L-1). In addition, the diagnostic capabilities of the sensor were evaluated in plasma rats from 31 individuals (16 chronically exposed to alcohol and 15 saline control), yielding a very good clinical sensitivity and specificity (81% and 87%, respectively). These results draw the potential of this approach to be used for POCT of alcohol abuse, making it a useful tool to help therapists/clinicians even patient's family in the follow-up of alcohol rehabilitation.