Gold Nanoparticles in Biosensors: A Systematic Review of Synthesis Methods, Electrode Modification, and Bioconjugation for Enhanced Detection

Biosensors are devices that can measure and quantify biomarkers specialized for infectious diseases. Nanoparticles are extensively utilized in biosensors due to their ability to achieve low detection limits. However, biosensor performance can be significantly impacted by challenges such as slow electron transfer kinetics and limited surface area for biomolecule immobilization. Gold nanoparticles (AuNPs) are a type of plasmonic nanoparticle with exceptional optical and physical properties, making them promising for biomedical and analytical applications. This review summarizes common AuNP synthesis methods, their integration into biosensors, and their impact on the biosensors' performance. A literature survey covering the period from 2020 to 2024 was conducted using the Scopus database to examine the synthesis and application of AuNPs in biosensors. A systematic review of 20 studies was performed following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The review identified nine articles related to the conjugation of AuNPs with bioreceptors. Additionally, studies focusing on AuNPs synthesis methods and electrode modifications were identified, with two papers that addressed both synthesis and bioconjugation. The findings suggest a need for future research to explore alternatives, such as biological approaches to AuNP synthesis, and to further investigate modifications of various electrode surfaces with AuNPs.