DEVELOPMENT OF GOLD NANOPARTICLE-BASED NANO-SENSOR FOR DETECTION OF POLYAMINES IN SALIVA AS A POTENTIAL MARKER FOR EARLY DIAGNOSIS OF ORAL CANCER

Abstract

Oral cancer accounts for 50–70% of all cancer-related deaths in India and ranks sixth among the most frequent cancers globally. Roughly 90% of oral malignancies are histologically determined to come from squamous cells and are therefore called oral squamous cell carcinoma. Organic polycations known as biogenic polyamines, for example, putrescine (Put), spermidine (Spd), and spermine (Spm), are vital for cell proliferation, including gene expression control, regulation of endonuclease-mediated fragmentation of DNA, and DNA damage inhibition. Higher Spm and Spd levels have been identified as cancer biomarkers for detecting tumour development in various cancers. This work used Tannic acid, a polyphenolic compound, as a reducing and capping agent to fabricate Au-NPs via a one-step microwave-assisted synthesis. The fabricated TA-Au-NPs were utilised as a nanoprobe for colourimetric sensing polyamines in PBS. When TA-Au-NPs are added to the polyamine, the amine groups in polyamines interact with the phenolic groups of TA-Au-NPs via hydrogen bonding or electrostatic interactions. These interactions cause the aggregation of TA-Au-NPs, resulting in a red shift of the SPR band of TA-Au-NPs from 530 nm to 560 nm. The nanoprobe was found to be highly specific for Spm at low concentrations. On recording the RGB values of the sensing process using a smartphone app, it was found that as the nanoparticles aggregated due to the presence of Spm or Spd, the intensity of the R-value decreased, indicating the aggregation of TA-Au-NPs due to interaction with the polyamines Spd and Spm.