Ramya Adukkadan N, Joseph Manu M, Nair Jyothi B, Karunakaran Varsha, Narayanan Nisha, Maiti Kaustabh Kumar
Chemical Sciences & Technology Division, CSIR-National Institute for Interdisciplinary Science & Technology (CSIR-NIIST) , Industrial Estate, Pappanamcode, Thiruvananthapuram 695019, Kerala, India.
Academy of Scientific and Innovative Research, AcSIR, CSIR-NIIST , Thiruvananthapuram 695019, Kerala, India.
ACS Appl Mater Interfaces. 2016 Apr 27;8(16):10220-5. doi: 10.1021/acsami.6b01908. Epub 2016 Apr 14.
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.
我们设计并合成了新型的四苯乙烯（TPE）修饰的有机荧光团，并揭示了它们在吸附于纳米粗糙金表面时通过表面增强拉曼散射（SERS）反映出的独特拉曼指纹图谱，这是除了其普遍存在的聚集诱导发光（AIE）和聚集导致猝灭（ACQ）现象之外的新见解。已经合成了一系列由不同电子供体组成的五个TPE类似物，例如（1）带有丙基的吲哚啉（TPE-In）、（2）带有硫辛酸的吲哚啉（TPE-In-L）、（3）带有Boc保护丙胺的吲哚啉（TPE-In-Boc）、（4）苯并噻唑（TPE-B）和（5）喹哪啶（TPE-Q）。有趣的是，所有五个TPE类似物都产生了多重拉曼信号模式，其中TPE-In-Boc在指纹区域的信号强度显著增加。使用金纳米颗粒作为SERS基底构建了一种高效的SERS纳米探针，并以TPE-In作为拉曼报告分子，其与一种特定的肽底物Cys-Ser-Lys-Leu-Gln-OH共轭，该底物以识别前列腺特异性抗原（PSA）而闻名。指定的纳米探针TPE-In-PSA@Au在PSA蛋白酶附近作为SERS“开/关”探针发挥作用，在SERS平台上以0.5 ng的检测限清晰地识别PSA表达。此外，TPE-In-PSA@Au纳米探针能够有效识别在人LNCaP细胞中过表达的PSA，这可以通过SERS光谱分析和SERS映射进行可视化。
