Ultrasensitive electrochemical determination of the cancer biomarker protein sPD-L1 based on a BMS-8-modified gold electrode

Paweł Niedziałkowski; Magdalena Bojko; Jacek Ryl; Anna Wcisło; Marta Spodzieja; Katarzyna Magiera-Mularz; Katarzyna Guzik; Grzegorz Dubin; Tad A Holak; Tadeusz Ossowski; Sylwia Rodziewicz-Motowidło

doi:10.1016/j.bioelechem.2021.107742

Ultrasensitive electrochemical determination of the cancer biomarker protein sPD-L1 based on a BMS-8-modified gold electrode

Bioelectrochemistry. 2021 Jun:139:107742. doi: 10.1016/j.bioelechem.2021.107742. Epub 2021 Jan 18.

Affiliations

¹ Department of Analytical Chemistry, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308 Gdansk, Poland. Electronic address: pawel.niedzialkowski@ug.edu.pl.
² Department of Biomedical Chemistry, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308 Gdansk, Poland.
³ Department of Electrochemistry, Corrosion and Materials Engineering, Faculty of Chemistry, Gdansk University of Technology, Narutowicza 11/12, Gdansk 80-233, Poland.
⁴ Department of Analytical Chemistry, Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308 Gdansk, Poland.
⁵ Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland.
⁶ Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387 Krakow, Poland; Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Krakow, Poland.

PMID: 33517203
DOI: 10.1016/j.bioelechem.2021.107742

Abstract

This work describes the modification of a gold electrode with the BMS-8 compound that interacts with the Programmed Death-Ligand 1 (PD-L1), an immune checkpoint protein. The results show that we can confirm the presence of the sPD-L1 in the concentration range of 10^-18 to 10^-8 M using electrochemical impedance spectroscopy (EIS) with a limit of detection (LOD) of 1.87 × 10^-14 M for PD-L1 (S/N = 3.3) and at a concentration of 10^-14 M via cyclic voltammetry (CV). Additionally, high-resolution X-ray photoelectron spectroscopy (XPS), contact angle, and surface free energy measurements were applied to confirm the functionalization of the electrode. We investigated the selectivity of the electrode for other proteins: Programmed Death-1 (PD-1), cluster of differentiation 160 (CD160), and B- and T-lymphocyte attenuator (BTLA) at concentrations of 10^-8 M. Differentiation between PD-L1 and PD-1 was achieved based on the analysis of the capacitance effect frequency dispersion at the surface of the modified Au electrode with BMS-8 after incubation at various concentrations of PD-L1 and PD-1 proteins in the range of 10^-18 to 10^-8 M. Significant differences were observed in the heterogeneity of PD-L1 and PD-1. The results of the quasi-capacitance studies demonstrate that BMS-8 strongly and specifically interacts with the PD-L1 protein.

Keywords: Cyclic voltammetry (CV); Cysteamine; Electrochemical impedance spectroscopy (EIS); Gold electrode modification; sPD-L1 protein.

MeSH terms

B7-H1 Antigen / analysis*
Biomarkers, Tumor / analysis
Biosensing Techniques / methods*
Dielectric Spectroscopy / methods*
Electric Capacitance
Electrochemical Techniques / methods*
Electrodes
Gold / chemistry
Humans
Limit of Detection
Metal Nanoparticles / chemistry
Neoplasms / diagnosis*
Programmed Cell Death 1 Receptor / analysis*
Sensitivity and Specificity

Substances

B7-H1 Antigen
Biomarkers, Tumor
CD274 protein, human
PDCD1 protein, human
Programmed Cell Death 1 Receptor
Gold