Mesoporous Hollow Carbon Nanospheres/Spiro Polymer-Based Immunosensors for Near-Field Communication (NFC)-Enabled Detection of Chronic Kidney Disease

Abstract

Chronic kidney disease (CKD) poses a significant burden on healthcare systems due to its high treatment costs and elevated mortality rates, particularly in advanced stages. Early diagnosis and continuous monitoring are critical for improving patient outcomes and reducing healthcare expenditures. Herein, we report the development of a portable, rapid, and user-friendly electrochemical immunosensor for point-of-care (POC) applications, enabling early-stage detection and monitoring of CKD. The sensor was constructed using mesoporous hollow carbon nanospheres (MHCNSs) with an average diameter of 442 +/- 28 nm and a nanoscale shell thickness of approximately 25 nm, featuring nanoscale pores within the mesoporous shell, together with a spiro-based conjugated polymer (P-SFXAlFlu). Subsequently, biofunctional and selective recognition surfaces were fabricated by bioconjugation of specific antibodies of CKD biomarkers, kidney injury molecule-1 (KIM-1), and neutrophil gelatinase-associated lipocalin (NGAL), onto the polymer matrix. Then, the developed immunosensor was integrated with an NFC-based potentiostat, enabling wireless and portable detection of KIM-1 and NGAL for POC use. The biosensor platform was characterized using analytical techniques to assess its structure and electrochemical performance. The P-SFXAlFlu/MHCNSs/Anti-KIM-1 and P-SFXAlFlu/MHCNSs/Anti-NGAL immunosensors exhibited high sensitivity, stability, and selectivity. The sensors displayed a broad detection range of 10-150 ng/mL for KIM-1 and 20-200 ng/mL for NGAL, with low limits of detection (LOD) of 3.09 and 13.02 ng/mL, respectively. Furthermore, excellent specificity toward target biomarkers was demonstrated. These findings highlight the potential of carbon-based electrochemical immunosensors as reliable, sensitive, and portable platforms for accurate and rapid CKD detection in clinical settings.