Impedimetric Screen-Printed Immunosensor for the Rapid Detection of Chagas Disease

FRANCHIN, LARA; CHAIN, CECILIA Y.; CISNEROS, JOSÉ SEBASTIÁN; VILLAGRA, ANDREA P. M.; LABRIOLA, CARLOS A.; PACCAGNELLA, ALESSANDRO; BONALDO, STEFANO

Roma

Conferencia; BIOSTEC 2024; 2024

Institute for Systems and Technologies of Information, Control and Communication (INSTICC) and technically co-sponsored by the IEEE SMC - TC on Cyber-Medical Systems

Chagas disease is an endemic parasitic condition affecting Latin America and recently Europe caused by the Trypanosoma cruzi. This work proposes a new impedimetric immunosensor for the rapid, cost-effective, label-free, and lowvolume detection of specific anti- T. cruzi antibodies, used as biomarkers of Chagas disease in human serum. The biosensor is based on gold screen-printed electrodes that are functionalized with isolated cruzipain proteins by adsorption, following a highlyreproducible 40 minutes- chemical procedure. The biosensor is tested with clinical serum samples from patients with (positive) or without (negative) anti- T. cruzi antibodies as previously verifiedby ELISA testing. The detection is performed through electrochemical impedance spectroscopy, showing 22% variation of the charge transfer resistance ( Rct ) for positive human serumdue to the immunoreaction between the immobilized cruzipain and the specific antibodies contained in the samples. Based on the cutoff value of Rct ratios, the developed immunosensor iscapable to successfully discriminate positive and negative human serum samples at a dilution factor of 1/6400 in phosphate buffered saline solution, showing an excellent agreement with the ELISA results. The kinetics of the binding between immobilized cruzipain and specific antibodies are also characterized, with an equilibrium dissociation constant (KD) of 12.59 nM and a negative cooperative binding indicated by a Hill coefficient of 0.85. The immunosensor demonstrates high sensitivity and specificity in detecting Chagas disease biomarkers in serum samples. The paper also discusses the cost-effectiveness of the immunosensor compared to ELISA, highlighting its potential as a point-of-care diagnostic tool for Chagas disease.