Smartphone controlled platform for point-of-care diagnosis of infectious diseases

Abstract

Abstract—In this work, we present the development of apoint-of-care platform for the serologic diagnosis of infectiousdiseases. The complete system consists of magnetic particles withimmobilized antigens, disposable electrochemical cells, hardwareand software. The main purpose of this paper is to present thelast two components. The platform is powered by a rechargeablebattery and can be controlled using mobile devices, allowingpoint-of-care diagnosis of diseases. The platform was successfullytested for the diagnosis of foot-and-mouth disease, human andbovine brucellosis, and Chagas disease.Keywords—Point-Of-Care Diagnosis; Electrochemical Biosen-sor; Portable platform; Android app I. I NTRODUCTION Biosensors are compact analytical devices which employa biological element in order to detect a specific substance,i.e. the analyte. After the analyte has been detected by thebiological recognition element, a signal of some sort is pro-duced which is then converted into an electrical signal witha transducer. In the case of electrochemical biosensors, thechemical signal generated by the interaction between the bio-logical recognition element and the analyte is then convertedinto an electrical current via an electrochemical reaction at anelectrode surface [1]. A particular case is the amperometricbiosensors, where the electrochemical measurement is carriedout by a potentiostat, which is an instrument that applies avoltage to a working electrode with respect to a reference elec-trode and measures the current flowing through that workingelectrode.Voltage is controlledby usingan auxiliaryor counterelectrode.Biosensors aimed for the detection of the presence ofspecific antibodies or antigens are particularly important forthe diagnosis of diseases in remote environments, wherecarrying out immunoassays such as ELISA (Enzyme-LinkedImmunosorbent Assay) is not an option. In addition to thepossibility to carry out diagnosis with minimum training andequipment, point-of-care devices have additional advantages.For instance, fast, non-expensive and multiple assays can beperformed with point-of-care portable devices, which can beof help in the occurrence of an epidemic spread.This article presents the development of a compact andwireless amperometric biosensors platform, with support forAndroid and other operating systems that allows to diagnoseinfectious diseases as foot-and-mouth disease, human andbovine brucellosis, and Chagas disease. Emphasis is placed onthe development of the hardware and its associated software,mentioning also the detection principle and other system com-ponents. Results obtained for those diagnosis are presented.II. D