Biosensing applications of gold-functionalized carbon-based composites.

Gold nanoparticles (AuNPs) have been utilized for sensing purposes and various applications. Some of the challenges associated with the use of pristine gold nanoparticles for sensing application are oxidation and rapid aggregation. Functionalization with various organic and inorganic materials have been used to overcome these challenges. Examples of such organic materials are the carbon-based materials such as activated carbon, graphene, CNT, graphitic carbon nitride, cyclodextrin, fullerenes, gels, polymers, alginates, chitosan, biochar, coal, resins/wood, metal organic framework, graphene oxide/reduced graphene oxide and cellulose. The present review gives detailed overview of the biosensing applications of gold nanoparticles functionalized with various carbon-based materials. Various methods of biosensing such as electrochemical (amperometry, potentiometric, voltametric and impedimetric) as well as mass-based biosensing methods, are comprehensively discussed. Then, the use of the gold/carbon-based materials in detecting oligonucleotides/DNA, tumour cells, protein/enzymes, glucose, thiol, peroxide and microbes such as bacteria and viruses are comprehensively reviewed.