# Electrochemical Nanostructured Aptasensor for Direct Detection of Glycated Hemoglobin

## TL;DR

A new electrochemical sensor was developed to directly detect glycated hemoglobin, a key diabetes biomarker, with high accuracy and ease of use.

## Contribution

The study introduces a novel nanostructured aptasensor combining carbon nanotubes and gold nanoparticles for improved HbA1c detection.

## Key findings

- The sensor has a wide linear range (0.688–11.5%) and a low detection limit (0.098%).
- It demonstrates good selectivity, stability, and successful application on real samples.
- The sensor is miniaturized, requires small sample volumes, and is suitable for on-site use.

## Abstract

Glycated hemoglobin (HbA1c) is an important biomarker applied for the diagnosis, evaluation, and management of diabetes; therefore, its accurate determination is crucial. In this study, an innovative nanoplatform was developed, integrating carbon nanotubes (CNTs) with enhanced hydrophilicity achieved through cyclodextrin (CD) functionalization, and combined with gold nanoparticles (AuNPs) electrochemically deposited onto a screen-printed carbon electrode. The nanomaterials significantly improved the analytical performance of the sensor due to their increased surface area and high electrical conductivity. This nanoplatform was employed as a substrate for the covalent attachment of thiolated ferrocene-labeled HbA1c specific aptamer through Au-S binding. The electrochemical signal of ferrocene was covered by a stronger oxidation peak of Fe2+ from the HbA1c structure, leading to the elaboration of a nanostructured aptasensor capable of the direct detection of HbA1c. The electrochemical aptasensor presented a very wide linear range (0.688–11.5%), an acceptable limit of detection (0.098%), and good selectivity and stability, being successfully applied on real samples. This miniaturized, simple, easy-to-use, and fast-responding aptasensor, requiring only a small sample volume, can be considered as a promising candidate for the efficient on-site determination of HbA1c.