Sialic Acid Sensing via Molecularly Imprinted Polymer on Laser‐Induced Graphene

ABSTRACT Sialic acid is an important biomarker for oral diseases, including cancer. We show that electropolymerization of aminophenylboronic acid onto laser‐induced graphene substrate in the presence of sialic acid results in the formation of a molecularly imprinted polymer. Removal of the template sialic acid makes the film capable of subsequent recognition of this analyte. Interaction of the sensor film with the analyte is then tracked using electrochemical approaches in the presence of an external redox‐couple, differential pulse voltammetry showing the clearest analytical signal (sensitivity of 14.113 µA/m m ). The studies comparing the imprinted and non‐imprinted samples show that the effect of imprinting is indeed the cause of the selective detection capabilities of the electropolymerized film, exhibiting an average imprinting factor of around 12.72. It is demonstrated that the sensor can measure sialic acid in a clinically relevant range of salivary concentrations (LOD = 0.598 m m ), being able to recognize threshold levels associated with cancerous processes. The sensor shows good selectivity to the chosen SA analyte in the tests with common saliva interferents: proteins and glucose. While performance in real samples of unstimulated whole saliva is lacking, the developed sensor shows potential for use in lab and point‐of‐care assessments.