Pornprom T.Phusi N.Thongdee P.Pakamwong B.Sangswan J.Kamsri P.Punkvang A.Suttisintong K.Leanpolchareanchai J.Hongmanee P.Lumjiaktase P.Jampasa S.Chailapakul O.Pungpo P.Mahidol University2023-09-262023-09-262024-01-15Talanta Vol.267 (2024)00399140https://repository.li.mahidol.ac.th/handle/20.500.14594/90201Tuberculosis (TB) currently remains a major life-threatening disease as it can be fatal if not treated properly or in a timely manner. Herein, we first describe a disposable and cost-effective paper-based electrochemical biosensor based on a gold particle-decorated carboxyl graphene (AuPs/GCOOH)-modified electrode for detecting heat shock protein (Hsp16.3), which is a specific biomarker indicating the onset of TB infection. The device pattern was first engineered to facilitate detection procedures and printed on low-cost filter paper to create hydrophobic and hydrophilic regions using a wax printing technique. Immunoassays proceeded in a half-sandwich format because it is a reagent-less approach and requires no labeling step. The fabrication of the immunosensor began with GCOOH drop casting, the electrochemical deposition of AuPs, and the establishment of a biorecognition layer against Hsp16.3 utilizing 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS)-sulfo standard chemistry. The appearance of Hsp16.3 resulted in a substantial decrease in the electrochemical signal response of the redox probe employed [Fe (CN)6]3−/4− due to the created immunocomplexes that possess insulation properties. GCOOH enables direct antibody immobilization, and AuPs enhance the electrochemical properties of the sensor. This proposed immunosensor, while requiring only a miniscule sample volume (5 μL), achieved superior performance in terms of the limit of detection, measuring at 0.01 ng/mL. Our platform was confirmed to be highly specific to Hsp16.3 and can rapidly detect TB-infected sera without necessitating any pre-enrichment (20 min), making it an alternative and particularly suitable for the early diagnosis of TB in resource-scarce countries.ChemistryArticleSCOPUS10.1016/j.talanta.2023.1252102-s2.0-85171322873