Hierarchical Graphene/Au/Polyaniline Nanostructured Electrode for Dual-Modality Electrochemical LAMP Biosensing of Helicobacter pylori

Abstract

Helicobacter pylori (HP) infection is directly associated with over 90% of all gastric cancer (GC) cases. Currently available HP tests are prone to false negatives and are inapt for decentralization. Reliable and user-friendly detection platforms for timely diagnosis and routine monitoring are critical to patient survival. Herein, we targeted this unmet need by developing a novel biosensing platform that strategically combined the robust versatility of electrochemical techniques with the sensitivity and specificity of loop-mediated isothermal amplification (LAMP) to enable the accurate detection of HP at the point-of-care (POC). The biosensor design consisted of an underlying screen-printed carbon electrode (SCPE), sequentially modified with (i) highly conductive acid-functionalized sp2 graphene (Gr) and (ii) needle-like gold microstructures encapsulated with (iii) pH-sensitive polyaniline (PANI), assembled between laser-cut cover layers with a built-in reaction chamber for facile sample handling and detection. LAMP was performed using synthesized primers targeting the HP glmM gene. The amplification inherently generates H⁺, triggering pH variations, which are precisely tracked by the developed biosensor to simultaneously monitor amplicon growth and quantify HP DNA concentrations via two modes: continuous mode and segmented mode. High sensitivity in a wide linear range (1 to 107 copies/μL) with a limit of detection (LOD) of 1 copy/μL is reported. Furthermore, the excellent correlation with clinical results underscored the practical feasibility of this platform to allow reliable early diagnosis of HP infections and serve as a viable alternative to gastric endoscopy.