JLU-PERS Group
Plasmon-enhanced Raman spectroscopy (PERS)@Jilin University
SERS for Single Cell study
1.Raman database for intracellular biological components
Accurate detection and analysis of biomolecules such as proteins, deoxyribonucleic acid (DNA), and some metabolites, especially their dynamic changes in molecular configurations, distributions, and interactions, are crucial for comprehensively understanding their roles in cellular physiological and pathological processes. Cytobiological methods for cell-related studies start with the extraction processes of intranuclear components with many cell lysis buffers, following with the structural characterizations and quantitative analysis of the extracted components.
SERS is a substrate-dependent method. Only the molecules adjacent to metal can be greatly amplified. To achieve the SERS information of intracellular components, we developed two strategies.
1) In situ measurement. We culture the cells with gold nanoprobe to the targeted position that we are interested in. Then we measure the signal from the target position.
(Anal. Chem. 2015, 87, 2504-2510; Anal. Chem. 2017, 89, 2844−2851; ACS Appl. Mater. Interfaces 2018, 10, 7910−7918)
2) Ex-situ one, we first isolated the cell nucleus and then mixed them with gold nanorods for the next SERS measurement.
(Anal. Bioanal. Chem., 2019, 411(23), 6021-6029)
2. Intracellular inspection during therapies at the organelle level
By analyzing the time-dependent SERS spectra during the therapeutic processes, information of many proteins and DNA molecules in cancer cell organelles have been revealed, from which we can preliminarily deduce that the drug treatment mechanism and cell damage pathway. (Anal. Chem. 2015, 87, 2504-2510; Anal. Chem. 2017, 89, 2844−2851; ACS Appl. Mater. Interfaces 2018, 10, 7910−7918; Front. in Chem. 2019, 6, 665; Analyst, 2019, 144, 5521-5527; Carbon, 2020, 156, 558-567.)
3. Quantitative analysis of small molecules in cell organelle
Many small molecules that are important in cell biology but hard to label on were detected by our developed SERS nanosensors. By decorating these plasmon-based nanosensors with the organelle-targeting feature, we can measure the local environments and the evolution of small molecules, e.g. pH, biothiols, and ROS, etc. (Nanoscale, 2018, 10, 1622–1630; Sensor & Actuator B, 2019, 285, 84-91; Sensor & Actuator B, 2019, 290, 527-534; Biosens. Bioelectron. 2020, DOI: 10.1016/j.bios.2019.111957)
4. Microdroplet-SERS for single-cell study
Single-cell metabolomics could be used to discover the chemical strategies of cells for coping with chemical or environmental stress because metabolomics provides a more immediate and dynamic picture of cell functionality. We presented a SERS-microfluidic droplet platform to isolate a single cell in one droplet to realize the SERS label or label-free analysis of multiplexed metabolites, secrets, membrane receptors at the single-cell level. This SERS-microdroplet platform is a powerful tool for exploring single-cell heterogeneity . (Lab Chip, 2019, 19, 335–342; Anal. Chem. 2019, 91, 2551−2558; Microchimica Acta, 2019, 186, 376; Anal. Chem. 2019, DOI:10.1021/acs.analchem.9b03294)
Plasmon coupling for high-performance SERS
Metal nanostructures with the configurations of narrow gaps or sharp tips attract plenty of researchers due to their superior performances in plasmonic sensing and surface-enhanced spectroscopy. To get better performances, one way is to fabricate sharper tips or narrower gaps, however, it poses a great challenge to nano-processing. Our study is to improve the SERS signals by considering the excitation and emission ways. We are trying to amplify the incident light field and increase the collection of scattering light. By consider the SERS physical enhancement mechanism, we started from the ways of plasmon coupling. Two strategies were explored. (1) The planar dielectric waveguide can harvest most incident light by a prism and generate an enhanced leaky mode evanescent field on the surface of the waveguide. The incident light field that can be improved about one order of magnitude is used for plasmon coupling, and SERS as well (J. Phys. Chem. Lett., 2013, 4, 3153-3157；J. Phys. Chem. C, 2015, 119, 24942-24949；Photonics Res., 2017, 5, 527-535；Sens. Actuators, B, 2019, 280, 144-150.). (2) By using a periodical plasmonic structure, we can tune the emission to a vertical direction by changing its periodic parameters [5-7], which can improve the collection efficiency by the directional emission of plasmons. These plasmon coupling ways bring many merits for SERS sensing, e.g. high sensitivity and many possibilities for the SERS detections of large molecules, etc. (Thin Solid Film 2012, 520, 6001; J. Phys. Chem. C, 2012, 116 (44), 23608–23615; Sci. Rep., 2017, 7, 14630.)
High-pressure spectroscopies for organic crystals
Organic solid-state luminescent materials have always been a hot topic due to their wide applications in the fields of organic optoelectronic devices and fluorescent sensors. Realizing flexible and tunable emission conversion in organic solid-state luminescent materials is always fascinating. To achieve multi-color regulation of solid-state emissions, different strategies have been exploited, such as (i) controlling the mode of molecular packing,13 (ii) aggregation-induced emission (AIE), (iii) restriction of intramolecular rotation (RIR), (iv) torsion/planarity of enol conformers, etc. We propose several studies relating to mechanochromic materials by using the diamond anvil cell (DAC) assisted spectroscopies, which paves a way of in-depth insight into the mechanism of mechanochromism and the structure-property relation in organic crystals. ( J. Phys. Chem. A 2015, 119, 1303−1308; J. Phys. Chem. A. 2015, 119 , 9218–9224; PCCP., 2018, 20, 13249-13254; PCCP., 2018, 20, 30297-30303; J. Mater. Chem. C, 2018, 33, 6, 8958-8965; Spectrochimica Acta A, 2018, 202, 70-75; Adv. Opt. Mater. 2018, 6, 1700647; J. Mater. Chem. C, 2019, 7, 275-280; Mater. Chem. Front., 2019, 3, 2128-2136; ACS Omega, 2019, 4, 6,10424-10430; Dye & Pigments, 2019, 170, 107603; Dye & Pigments, 2019, 162, 831-836; Dye & Pigments, 2019, 161, 182-187; Dye & Pigments, 2019, DOI10.1016/j.dyepig.2019.108116; Mater. Horizon, 2019, DOI: 10.1039/C9MH01041F; Mater. Chem. Front. 2020 DOI:10.1039/C9QM00529C)
