Single-molecule Surface-Induced Fluorescence Attenuation Based on Reduced Graphene Oxide

TL;DR

This paper improves single-molecule surface-induced fluorescence attenuation (smSIFA) by using thermally reduced graphene oxide to precisely control quenching distances, enabling better detection of biomolecular conformational changes.

Contribution

The study introduces a method to tune smSIFA's detection range by adjusting the reduction temperature of graphene oxide, enhancing its application in biomolecular studies.

Findings

Reduced graphene oxide's quenching distance can be precisely controlled.

Enhanced smSIFA detects conformational changes in Holliday junctions.

The method improves detection accuracy for vertical biomolecular movements.

Abstract

Single-molecule surface-induced fluorescence attenuation (smSIFA) is a precise method for studying the vertical movement of biological macromolecules using two-dimensional material acceptors. Unlike other methods, smSIFA is not influenced by the planar motion of membranes or proteins. However, the detection range and accuracy of vertical movement are dependent on the properties of these two-dimensional materials. Recently, smSIFA utilizing graphene oxide and graphene has significantly advanced the study of biomacromolecules, although the detection range is restricted by their inherent quenching distances. Modifying these distances necessitates the replacement of the medium material, which presents challenges in material selection and preparation. Consequently, there is a pressing need to develop controllable materials for smSIFA applications. In this study, we enhance the smSIFA technique using graphene oxide as the medium acceptor through thermal reduction. By adjusting the reduction temperature, we prepare reduced graphene oxides at varying degrees of reduction, thus fine-tuning the quenching distances. The adjustment of these distances is measured using fluorescently labeled DNA. This modified smSIFA approach, employing reduced graphene oxide, is then applied to observe conformational changes in the Holliday junction, demonstrating the enhanced detection capabilities of reduced graphene oxide.