Nanodot zirconium trisulfide based highly efficient biosensor for early diagnosis of lung cancer

Abstract

In present work, we report results of the studies related to the synthesis of nanodot metal chalcogenide (zirconium trisulfide, ∼5.7 nm in size) based biosensing platform for early detection of lung cancer serum biomarker (CKAP4). The nanodot zirconium trisulfide (nZrS3) was synthesized through low temperature hydrothermal method (200 °C for 72 h) and functionalized with 3-aminopropyl triethoxysilane (APTES) molecules via chemical process. To fabricate thin and uniform film onto the pre-hydrolyzed indium tin oxide (ITO) coated glass electrode of functionalized nanomaterials (APTES/nZrS3), an optimized electrophoretic condition (25 V for 60 s) was applied. Further, for covalent immobilization of anti-CKAP4 onto the APTES/nZrS3/ITO electrode, EDC-NHS chemistry was used and for blocking of non-specific binding sites, bovine serum albumin (BSA) was non-covalently immobilized via drop-cast method. The synthesized as well as functionalized nanomaterial and fabricated electrodes were characterized through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. Further, the electrochemical response studies of developed biosensing platform i.e., BSA/anti-CKAP4/APTES/nZrS3/ITO were carried out through DPV technique. The biosensing platform has ability to detect CKAP4 biomarker in the range of 100 pg mL−1-800 pg mL−1 with ultra-sensitivity of 68.76 µA [log (pg mL−1)]−1cm−2, notable lower detection limit of 86 pg mL−1 and shelf life upto 36 days. Moreover, the electrochemical data obtained, exhibit a good correlation with the concentrations of the cancer biomarker CKAP4 found in lung cancer patients as determined by the enzyme-linked immunosorbent assay (ELISA) technique.