New Insight of Tetraphenylethylene-based Raman Signatures for Targeted SERS Nanoprobe Construction Toward Prostate Cancer Cell Detection

• Published in: ACS applied materials & interfaces Vol. 8; no. 16; pp. 10220 - 10225
• Main Authors: Ramya, Adukkadan N., Joseph, Manu M., Nair, Jyothi B., Karunakaran, Varsha, Narayanan, Nisha, Maiti, Kaustabh Kumar
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 27-04-2016
• Subjects: Cell Line, Tumor; Gold; Humans; Male; Nanostructures; Oligopeptides; Prostatic Neoplasms; Spectrum Analysis, Raman; Stilbenes; PSA peptide sequence; cancer detection; tetraphenylethylene; gold nanoparticle; SERS
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.6b01908

We have designed and synthesized novel tetraphenylethylene (TPE) appended organic fluorogens and unfold their unique Raman fingerprinting reflected by surface-enhanced Raman scattering (SERS) upon adsorption on nanoroughened gold surface as a new insight in addition to their prevalent aggregation-induced emission (AIE) and aggregation-caused quenching (ACQ) phenomena. A series of five TPE analogues has been synthesized consisting of different electron donors such as (1) indoline with propyl (TPE-In), (2) indoline with lipoic acid (TPE-In-L), (3) indoline with Boc-protected propyl amine (TPE-In-Boc), (4) benzothaizole (TPE-B), and (5) quinaldine (TPE-Q). Interestingly, all five TPE analogues produced multiplexing Raman signal pattern, out of which TPE-In-Boc showed a significant increase in signal intensity in the fingerprint region. An efficient SERS nanoprobe has been constructed using gold nanoparticles as SERS substrate, and the TPE-In as the Raman reporter, which conjugated with a specific peptide substrate, Cys-Ser-Lys-Leu-Gln-OH, well-known for the recognition of prostate-specific antigen (PSA). The designated nanoprobe TPE-In-PSA@Au acted as SERS “ON/OFF” probe in peace with the vicinity of PSA protease, which distinctly recognizes PSA expression with a limit of detection of 0.5 ng in SERS platform. Furthermore, TPE-In-PSA@Au nanoprobe was efficiently recognized the overexpressed PSA in human LNCaP cells, which can be visualized through SERS spectral analysis and SERS mapping.