A FACILE LABEL-FREE ELECTROCHEMICAL APTASENSOR FOR THE DETECTION OF MARINE BIOLOGICAL TOXINS BASED ON NANOPOROUS GOLD-MODIFIED ELECTRODE

• Grant number: 24/06773-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date until: March 01, 2025
• End date until: February 28, 2027
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Mauro Bertotti
• Grantee: Girma Selale Geleta
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 23/00246-1 - Miniaturized large-scale devices for in-situ analysis: fabrication, characterization and applications, AP.TEM

Abstract

This study focuses on developing integrated miniaturized electrochemical aptasensors for quantifying marine toxins at trace levels. These toxins are ubiquitous, commonly found in water and seafood, potentially threatening human health and ecosystem safety. The proposed devices will consist of miniaturized electrochemical (bio) sensors, emphasizing building prototypes with reliable operation and high robustness for large-scale fabrication and in-field application. Porous gold nanostructures will be synthesized to modify the electrode surface to achieve high sensitivity toward the desired analytes (in our case, marine toxins). Nanoporous gold (NPG) nanostructures will be synthesized via a simple procedure that involves acidic treatment of a commercially available complex white gold alloy. The surface morphology, size, and shape of the mesopores and the surface roughness of the prepared porous gold samples will be characterized using SEM and AFM. Taking advantage of the porous gold characteristics such as high surface area, high electrocatalytic activity with tunable pore morphology, and easy functionalization ability of the porous gold nanostructures can be employed to modify the electrode surface and fabricate electrochemical sensors for detecting marine toxins with high sensitivity. The specificity and selectivity of electrochemical biosensors for targeting marine toxins can be achieved by combining nanoporous gold (NPG) with thiolated aptamers. Then, different relevant strategies will be investigated to integrate the developed NPG-based aptasensing probes into microfluidic systems to enable marine toxin detection in more complex samples with high analytical frequency. The main subjects are i. Developing miniaturized sensors for obtaining in situ and real-time concentrations of marine toxins in water and seafood; ii. An electrochemical aptasensor based on nanoporous gold can be coupled into paper substrates and with microfluidic structures. In this context, this study aimed to develop an electrochemical aptasensing platform composed of gold nanopores coated with specific thiolated aptamers to detect marine toxins in seafood and water samples.