title: Early diagnosis of oral cancer based on the surface plasmon resonance of gold nanoparticles.
abstract: The high mortality rate in cancer such as oral squamous cell carcinoma is commonly attributed to the difficulties in detecting the disease at an early treatable stage. In this study, we exploited the ability of gold nanoparticles to undergo coupled surface plasmon resonance and set up strong electric fields when closely-spaced to improve the molecular contrast signal in reflectance-based imaging and also to enhance the Raman signal of bioanalytes in cancer. Colloidal gold nanoparticles were synthesized and conjugated to anti-epidermal growth factor receptor (EGFR) for imaging. A self-assembled surface enhanced Raman scattering (SERS)-active gold nanoparticle monolayer film was also developed as a biosensing surface using a simple drop-dry approach. We have shown that gold nanoparticles could elicit an optical contrast to discriminate between cancerous and normal cells and their conjugation with antibodies allowed them to map the expression of relevant biomarkers for molecular imaging under confocal reflectance microscopy. We have also shown that the SERS spectra of saliva from the closely-packed gold nanoparticles films was differentiable between those acquired from normal individuals and oral cancer patients, thus showing promise of a simple SERS-based saliva assay for early diagnosis of oral cancer.
authors.affiliation: Division of Bioengineering, National University of Singapore, Singapore.
authors.forename: James Chen Yong
authors.initials: JC
authors.lastname: Kah
authors.forename: Kiang Wei
authors.initials: KW
authors.lastname: Kho
authors.forename: Caroline Guat Leng
authors.initials: CG
authors.lastname: Lee
authors.forename: Colin
authors.initials: C
authors.lastname: James
authors.forename: Richard
authors.initials: R
authors.lastname: Sheppard
authors.forename: Ze Xiang
authors.initials: ZX
authors.lastname: Shen
authors.forename: Khee Chee
authors.initials: KC
authors.lastname: Soo
authors.forename: Malini Carolene
authors.initials: MC
authors.lastname: Olivo
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000378:metabolism; D045744:Cell Line, Tumor; D006046:Gold; D006801:Humans; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D053758:Nanoparticles; D012463:Saliva / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D006046:Gold