• Niedzialkowski, Pawel
• Rodziewicz-Motowidło, Sylwia
• Ryl, Jacek
• Ossowski, Tadeusz
• Bojko, Magdalena
• Wcisło, Anna
• Magiera-Mularz, Katarzyna
• Spodzieja, Marta
• Guzik, Katarzyna
• Dubin, Grzegorz
• Holak, Tad

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.

Topics

• dispersion
• surface
• compound
• cluster
• x-ray photoelectron spectroscopy
• gold
• electrochemical-induced impedance spectroscopy
• functionalization
• cyclic voltammetry