Inosine-Assisted Signal-On Electrochemical Biosensor for Selective Bacterial DNA Detection Seçici Bakteriyel DNA Tespiti Amacıyla Geliştirilmiş İnosin Tabanlı Sinyal-Artışlı Elektrokimyasal Biyosensör
Fabad Journal of Pharmaceutical Sciences, cilt.51, sa.2, ss.819-838, 2026 (Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 51 Sayı: 2
- Basım Tarihi: 2026
- Doi Numarası: 10.55262/fabadeczacilik.1945136
- Dergi Adı: Fabad Journal of Pharmaceutical Sciences
- Derginin Tarandığı İndeksler: Scopus, EMBASE, Health Research Premium Collection (ProQuest), Pharma Collection (ProQuest)
- Sayfa Sayıları: ss.819-838
- Anahtar Kelimeler: bacterial diagnostic, carbon nanomaterials, Electrochemical sensing, label-free DNA detection, pathogen identification
- Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
- Dokuz Eylül Üniversitesi Adresli: Evet
Özet
Accurate and rapid identification of Shigella sonnei and Stenotrophomonas maltophilia remains challenging due to their close genomic similarity to other Gram-negative bacteria and their limited coverage in routine molecular diagnostic panels. In this study, we report a label-free electrochemical DNA biosensing strategy for the sequence-selective detection detection of these two clinically relevant but under-recognized pathogens. The biosensor is based on a pencil graphite electrode modified with carboxyl-functionalized single-walled carbon nanotubes (SWCNT-COOH), providing a conductive and chemically active interface for probe immobilization. To minimize intrinsic guanine-related background signals, inosine-substituted DNA probes were employed, enabling a hybridization-induced “signal-on” response that arises exclusively from the target DNA. Stable and reproducible probe attachment was achieved through optimized –COOH/–NH_2 interactions between the SWCNT interface and amine-terminated probes. Under optimized conditions, the biosensor exhibited linear responses in the 20–80 µg/mL range, with limits of detection of 6.1 µg/mL for S. sonnei and 8.4 µg/mL for S. maltophilia. The platform demonstrated effective discrimination against mismatched and non-complementary sequences and retained analytical performance in artificial saliva matrices, supporting its applicability in non-invasive sample environments. This work presents a simple and low-cost electrochemical approach for DNA-based detection of S. sonnei and S. maltophilia. The proposed sensing strategy highlights the potential of inosine-assisted, signal-on electrochemical readout as a modular platform for nucleic-acid detection, with relevance for decentralized and resource-limited diagnostic settings.