Photoinduced Enhanced Raman Probe for Use in Highly Specific and Sensitive Imaging for Tyrosine Dimerization in Inflammatory Cells.

A background-free photoinduced enhanced Raman (PIER) probe for highly sensitive detection of tyrosine dimerization process due to oxidative reaction in inflammatory cells is presented. The PIER probe could monitor oxidative reaction in real time by producing time-resolved spectral with discrete changes in Raman intensity. To the best of our knowledge, this is the first report on C≡C probes with PIER and vastly improved Raman activity. These results will contribute to the cutting edge of development of stable and highly sensitive chemical imaging technology.

Reversible detection of phosphorylation and dephosphorylation by tip-enhanced Raman spectroscopy using a cyclopentadienyl ruthenium nanotag functionalized tip.

The detection of cancer invasion is crucial for diagnosis. In this report, we employed a TERS tip and SERS nanotags to create a cell signaling based nano-sensing system. This system is capable of creating a reversible phosphorylation/de-phosphorylation cycle for TERS measurement. The reversible TERS sensing is then paired with a downstream binding domain, Src homology region 2 (SH2), which is associated with the cell signaling for cancer cell invasion. Such a system offers the advantages of convenient detection of nanotags and high sensitivity as validated in a cell model.

Operando characterization of chemical reactions in single living cells using SERS.

Detection of chemical reactions in living cells is critical in understanding physiological metabolic processes in the context of nanomedicine. Carbon monoxide (CO) is one of the important gaseous signaling molecules. Surface-enhanced Raman spectroscopy (SERS)-based CO-releasing nanoparticles (CORN) is utilized to investigate the chemical reaction of CO delivery in live cells. Using SERS CORN, carbonyl dissociation from CORN-Ag-CpW(CO)3 to CORN-Ag-CpW(CO)2 in live cells is observed. The subsequent irreversible degradation to CO-free CORN is a consequence of oxidative stress in cells. This observation affirms the step transition of CORN-Ag-CpW(CO)3 in cellular: CORN-Ag-CpW(CO)3 first proceeds via a direct loss of one CO followed by a oxidative decomposition giving rise to CORN-Ag-WO3 and as well as the release of one equivalents of CO. Importantly, the decarbonylation process can be correlated with the level of inflammatory biomarkers. For the first time, we provide unambiguous evidence for the steps transition of CO-release mechanism in cellular.