A simple label-free electrochemical sensor for sensitive detection of alpha-fetoprotein based on specific aptamer immobilized platinum nanoparticles/carboxylated-graphene oxide

Adisorn Tuantranont,Jantima Upan,Philippe Banet,Napaporn Youngvises,Pierre-Henri Aubert,Chanpen Karuwan,Jaroon Jakmunee

doi:10.1038/s41598-021-93399-y

Abstract

A label-free electrochemical aptamer-based sensor has been fabricated for alpha-fetoprotein (AFP) detection. Platinum nanoparticles on carboxylated-graphene oxide (PtNPs/GO-COOH) modified screen-printed graphene-carbon paste electrode (SPGE) was utilized as an immobilization platform, and the AFP aptamer was employed as a bio-recognition element. The synthesized GO-COOH helps to increase the surface area and amounts of the immobilized aptamer. Subsequently, PtNPs are decorated on GO-COOH to enhance electrical conductivity and an oxidation current of the hydroquinone electrochemical probe. The aptamer selectively interacts with AFP, causing a decrease in the peak current of the hydroquinone because the binding biomolecules on the electrode surface hinder the electron transfer of the redox probe. Effects of aptamer concentration and AFP incubation time were studied, and the current changes of the redox probe before and after AFP binding were investigated by square wave voltammetry. The developed aptasensor provides a linear range from 3.0–30 ng mL−1 with a detection limit of 1.22 ng mL−1. Moreover, the aptamer immobilized electrode offers high selectivity to AFP molecules, good stability, and sensitive determination of AFP in human serum samples with high recoveries.

Highlights

Hepatocellular carcinoma (HCC) is considered the most common primary cancer of the liver that causes people’s deaths worldwide
We developed a novel label-free electrochemical aptasensor to sensitively determine AFP using a highly specific aptamer and nanocomposites of platinum nanoparticles on carboxylated-graphene oxide (PtNPs/GO-COOH)
Carboxylated-graphene oxide was synthesized to obtain plenty of carboxylic groups on the graphene oxide that would efficiently promote immobilizing aptamer molecules to improve the detection sensitivity. Some metal nanoparticles such as gold, platinum, and palladium incorporated with carboxylated-graphene oxide were investigated to increase the current response of the hydroquinone that was used as a redox probe

Summary

Introduction

Hepatocellular carcinoma (HCC) is considered the most common primary cancer of the liver that causes people’s deaths worldwide. We developed a novel label-free electrochemical aptasensor to sensitively determine AFP using a highly specific aptamer and nanocomposites of platinum nanoparticles on carboxylated-graphene oxide (PtNPs/GO-COOH). To carry out the electrochemical detection of AFP, the initial peak current response, I0, before AFP incubation was recorded in 50 μL of 3 mM hydroquinone (prepared in PBS solution) by scanning a square wave voltammetric (SWV) potential from -1.0 to + 1.0 V.

Results

Conclusion