Highly sensitive photoelectrochemical immunosensor for detecting cancer marker CA19-9 based on a new SnSe quantum dot

• DOI: 10.1007/s00604-023-05718-x
• Publication Date: 2023-03-24T08:04:27Z
• Authors: Danial Gholamin; Pari Karami; Yasamin Pahlavan; Mohammad Johari-Ahar
• Keywords: Immunoassay; CA-19-9 Antigen; Tin; Neoplasms; Quantum Dots; Carbohydrates; Humans; Metal Nanoparticles; Biosensing Techniques; Electrochemical Techniques; 3. Good health

A sandwich-type photoelectrochemical (PEC) immunosensor was constructed on a screen-printed electrode (SPE) using gold-coated tin selenide quantum dots (Au-SnSe QDs) to determine the carbohydrate antigen 19 9 (CA19-9). Water-soluble Au-SnSe QDs were prepared by coating low-cost SnSe QDs, prepared by reacting tin(II) 2-ethyl hexanoate with selenium ions (HNaSe) without needing to add an external capping agent (SnSe QDs). SnSe-based QDs were characterized using high-resolution transmission electron microscopy (HR-TEM) and dynamic light scattering (DLS). DSP (dithio-bis (succinimidyl propionate)) as a linker was attached on Au@SnSe QDs and conjugated with CA19-9 monoclonal antibodies (Ab2-DSP-Au@SnSE QD). For capture probe assembling, an Au nano-layer was electrochemically deposited on a SPE by HAuCl4 reduction using 12 cycles of cyclic voltammetry (0 to - 1.4 V) at the scan rate of 50 mV s-1, then covered by self-assembly of DSP and covalent conjugation of CA19-9 Ab1. Our developed PEC immunosensor showed a significant photoelectrochemical response, recorded using chronoamperometry (0.3 V), for the presence of CA19-9 antigen in serum samples under light irradiation, with a detection limit (LOD) of 0.0011 U mL-1 and a dynamic range of 0.005-100 U mL-1. The recovery of CA19-9 determination from serum samples was 101 to 113%.