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A Gold Nanoparticle-Based Cortisol Aptasensor for Non-Invasive Detection of Fish Stress

Authors :
Yuki Tanaka
Nur Asinah binte Mohamed Salleh
Marie Ruoyun Tan
Shubha Vij
Caroline Lei Wee
Laura Sutarlie
Xiaodi Su
Source :
Biomolecules, Vol 14, Iss 7, p 818 (2024)
Publication Year :
2024
Publisher :
MDPI AG, 2024.

Abstract

Cortisol is a key stress biomarker in humans and animals, including fishes. In aquafarming, stress monitoring using cortisol quantification can help to optimize aquaculture practices for welfare and productivity enhancement. However, most current methods for cortisol detection rely on invasive tissue sampling. In this work, we developed a gold nanoparticle (AuNP)-based cortisol sensor to address the demand of detecting picomolar ranges of cortisol from complex fish tank water matrices as a non-invasive alternative for more effective stress monitoring. We first identified a DNA aptamer with effective binding to cortisol and then conjugated the thiol-labelled aptamer to AuNPs together with a blocker molecule (CALNN) to form an Au-Apt-CALNN conjugate that is stable in fish tank water. The cortisol detection principle is based on magnesium chloride (MgCl2)-induced particle aggregation, where the cortisol-bound aptamer on the AuNPs folds into a tertiary structure and provides greater protection for Au-Apt-CALNN against MgCl2-induced aggregation due to steric stabilization. At an optimum MgCl2 concentration, the differential stability of particles with and without cortisol binding offers a limit of detection (LOD) of 100 pM for cortisol within a 35 min reaction. The aptasensor has been validated on recirculating aquaculture system (RAS) fish tank water samples by the HPLC method and was able to detect changes in water cortisol induced by two different stress paradigms. This on-site deployable and non-invasive sensor offers opportunities for more efficient and real-time fish stress monitoring for the optimization of aquaculture practices.

Details

Language :
English
ISSN :
2218273X and 04908414
Volume :
14
Issue :
7
Database :
Directory of Open Access Journals
Journal :
Biomolecules
Publication Type :
Academic Journal
Accession number :
edsdoj.049084141def4e92846f80410012bc1b
Document Type :
article
Full Text :
https://doi.org/10.3390/biom14070818