Chemical Engineering Journal, cilt.529, 2026 (SCI-Expanded, Scopus)
A straightforward label-free assay for detecting cardiac biomarker troponin T (cTnT) was developed using a smartphone-controlled electrochemical sensor fully controlled via Near Field Communication (NFC). The integrated system consisted of a smartphone, an electrode sensor modified with a cTnT aptamer, and a card-sized electrochemical NFC tag sensor. Screen-printed electrode (SPE) surfaces were modified by co-immobilizing liquid metal BiSn core–shell particles and gold nanoparticles. This modified surface was subsequently functionalized with cTnT aptamer using mercaptohexanol (MCH) as a linker. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to confirm the immobilization and alteration procedures. The performance of the developed biosensor was evaluated by detecting cTnT in human serum samples using an Android smartphone's data display and a small NFC reader, demonstrating its potential for clinical diagnostics. The electrochemical signal was quantified by chronoamperometric detection using the NFC-based electrochemical aptasensor, by measuring the current response of the (Fe (CN)6)3−/4− redox pair before and after target addition. The sensor exhibited a limit of detection of 1.27 ng/mL for cTnT, with a linear calibration range from 0.075 to 10 ng/mL. Using a low-cost, smartphone-controlled sensor system, this electrochemical aptasensor offers a portable, straightforward, sensitive, and selective platform capable of evaluating a wide range of health biomarkers.