Controlling the Binding Efficiency of Surface Confined Antibodies through the Design of Mixed Self-Assembled Monolayers

A plethora of different electronic and optoelectronic devices have been developed lately, for biosensing applications (e.g., label-free, fast, and easier to operate) based on a detecting interface accommodating the biorecognition elements, anchored by thiolate self-assembled monolayers (SAMs) on a gold surface. Here, a surface plasmon resonance (SPR) characterization of anti-p24 anchored on different SAMs is performed to investigate the effect of the SAM structure on the antibodies’ packing efficiency and the sensors’ analytical figures of merit. Notably, the mixed SAM deposited from a solution 10:1 of 3-mercaptopropionic acid and 11-mercaptoundecanoic acid (11MUA) is compared to that resulting from a solution 10:1 of ad hoc synthesized N-(2-hydroxyethyl)-3-mercaptopropanamide (NMPA)/11MUA. Despite the improvement in the anti-p24 surface coverage registered using the 11MUA/NMPA SAM, the latter produces a significant decrease in the antibodies’ binding efficiency against human immunodeficiency virus p24 protein. To provide a molecular rationale behind the SPR data, density functional theory calculations are also undertaken. A comprehensive physical view of the main competing phenomena affecting the biorecognition events at a biofunctionalized gold detecting interface is represented here.

Publication year: 2023
Authors: Sarcina L. 1, Delre P. 2, Graziano G. 3, Stefanachi A. 3, Blasi D. 1, Picca R.A. 1, Di Franco C. 2, Leonetti F. 3, Scamarcio G. 4,5, Bollella P. 1,5, Mangiatordi G.F. 2, Macchia E. 3,5,6, Torsi L. 1,5,6

1 – Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Bari, 70126 Italy
2 – CNR—Institute of Crystallography, Via Amendola 122/o, Bari, 70126 Italy
3 – Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Bari, 70126 Italy
4 – Dipartimento Interateneo di Fisica “M. Merlin”, Università degli Studi di Bari Aldo Moro, Bari, 70126 Italy
5 – Centre for Colloid and Surface Science, Università degli Studi di Bari Aldo Moro, Bari, 70126 Italy
6 – The Faculty of Science and Engineering, Åbo Akademi University, Turku, 20500 Finland

Published in: Advanced Materials Interfaces, 2023, Vol. 10, Issue 12, 2300017
DOI: 10.1002/admi.202300017


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