Abstract
The fabrication of surface enhanced Raman spectroscopy (SERS) substrates with controlled high density hot spots still remains challenging. Herein, we report highly effective SERS substrates containing the self-generating (SG) nanogaps from polystyrene nanosphere monolayer through isotropic plasma etching. The emergence of multimode hot spots, i.e., metal film over nanosphere (MFON)-like hot spots (closed gaps, 0 nm), individual self-aligned hot spots (discrete gaps, > 20 nm) and three-dimensional (3D) hot spots (nanogaps, 1–10 nm), makes the SG SERS substrates superior as compared to the traditional MFON or the well-ordered self-aligned SERS substrates in terms of enhancement, uniformity, and reproducibility. The SG SERS substrates can function as the excellent SERS platforms for trace molecule detection in the practical application fields.

Similar content being viewed by others
References
Fleischmann M., Hendra P. J., McQuillan A. J. Raman-spectra of pyridine adsorbed at a silver ELectrode. Chem. Phys. Lett. 1974, 26, 163–166.
Kleinman S. L., Ringe E., Valley N., Wustholz K. L., Phillips E., Scheidt K. A., Schatz G. C., Van Duyne R. P. Single-molecule surface-enhanced Raman spectroscopy of crystal violet isotopologues: Theory and experiment. J. Am. Chem. Soc. 2011, 133, 4115–4122.
Liu Y., Tian X. R., Guo W. R., Wang W. Q., Guan Z. Q., Xu H. X. Real-time Raman detection by the cavity mode enhanced Raman scattering. Nano Res. 2019, 12, 1643–1649.
Kurouski D., Zaleski S., Casadio F., Van Duyne R. P., Shah N. C. Tip-enhanced raman spectroscopy (TERS) for in situ identification of indigo and iron gall ink on paper. J. Am. Chem. Soc. 2014, 136, 8677–8684.
Wang H. Y., Zhou Y. F., Jiang X. X., Sun B., Zhu Y., Wang H., Su Y. Y., He Y. Simultaneous capture, detection, and inactivation of bacteria as enabled by a surface-enhanced Raman scattering multifunctional chip. Angew. Chem., Int. Ed. 2015, 54, 5132–5136.
Schatz, G. C.; Van Duyne, R. P. Electromagnetic mechanism of surface-enhanced spectroscopy. In Handbook of Vibrational Spectroscopy. Chalmers, J. M.; Griffiths, P. R., Eds.; John Wiley & Sons: Chichester, 2002; pp 759–774.
Im H., Bantz K. C., Lindquist N. C., Haynes C. L., Oh S. H. Vertically oriented sub-10-nm plasmonic nanogap arrays. Nano Lett. 2010, 10, 2231–2236.
Chirumamilla M., Toma A., Gopalakrishnan A., Das G., Zaccaria R. P., Krahne R., Rondanina E., Leoncini M., Liberale C., De Angelis F., et al. 3D nanostar dimers with a sub-10-nm gap for single-/few-molecule surface-enhanced Raman scattering. Adv. Mater. 2014, 26, 2353–2358.
Yan Z. X., Zhang Y. L., Wang W., Fu X. Y., Jiang H. B., Liu Y. Q., Verma P., Kawata S., Sun H. B. Superhydrophobic SERS substrates based on silver-coated reduced graphene oxide gratings prepared by two-beam laser interference. ACS Appl. Mater. Interfaces 2015, 7, 27059–27065.
Sharma B., Cardinal M. F., Kleinman S. L., Greeneltch N. G., Frontiera R. R., Blaber M. G., Schatz G. C., Van Duyne R. P. High-performance SERS substrates: Advances and challenges. MRS Bull. 2013, 38, 615–624.
Yu J., Yang M. S., Li Z., Liu C. D., Wei Y. S., Zhang C., Man B. Y., Lei F. C. Hierarchical particle-in-quasicavity architecture for ultratrace in situ Raman sensing and its application in real-time monitoring of toxic pollutants. Anal. Chem. 2020, 92, 14754–14761.
Jiang B., Xu L., Chen W., Zou C., Yang Y., Fu Y. Z., Huang S. M. Ag+-assisted heterogeneous growth of concave Pd@Au nanocubes for surface enhanced Raman scattering (SERS). Nano Res. 2017, 10, 3509–3521.
Wang Y. D., Zhang M. Y., Lai Y. K., Chi L. F. Advanced colloidal lithography: From patterning to applications. Nano Today 2018, 22, 36–61.
Wang Y. D., Lu N., Wang W. T., Liu L. X., Feng L., Zeng Z. F., Li H. B., Xu W. Q., Wu Z. J., Hu W., et al. Highly effective and reproducible surface-enhanced Raman scattering substrates based on Ag pyramidal arrays. Nano Res. 2013, 6, 159–166.
Wang Y. D., Lu N., Xu H. B., Shi G., Xu M. J., Lin X. W., Li H. B., Wang W. T., Qi D. P., Lu Y. Q., et al. Biomimetic corrugated silicon nanocone arrays for self-cleaning antireflection coatings. Nano Res. 2010, 3, 520–527.
Wang Y. D., Zeng Z. F., Li J., Chi L. F., Guo X. H., Lu N. Biomimetic antireflective silicon nanocones array for small molecules analysis. J. Am. Soc. Mass Spectrom. 2013, 24, 66–73.
Ellinas K., Tserepi A., Gogolides E. From superamphiphobic to amphiphilic polymeric surfaces with ordered hierarchical roughness fabricated with colloidal lithography and Plasma nanotexturing. Langmuir 2011, 27, 3960–3969.
Choi D. G., Jang S. G., Kim S., Lee E., Han C. S., Yang S. M. Multifaceted and nanobored particle arrays sculpted using colloidal lithography. Adv. Funct. Mater. 2006, 16, 33–40.
Zhang X. Y., Yonzon C. R., Van Duyne R. P. Nanosphere lithography fabricated plasmonic materials and their applications. J. Mater. Res. 2006, 21, 1083–1092.
Fang Y., Seong N. H., Dlott D. D. Measurement of the distribution of site enhancements in surface-enhanced Raman scattering. Science 2008, 321, 388–392.
Fang Y., Yang H. T., Jiang P., Dlott D. D. The distributions of enhancement factors in close-packed and nonclose-packed surface-enhanced Raman substrates. J. of Raman Spectrosc. 2012, 43, 389–395.
Ding T., Herrmann L. O., De Nijs, B., Benz F., Baumberg J. J. Self-aligned colloidal lithography for controllable and tuneable plasmonic nanogaps. Small 2015, 11, 2139–2143.
Plettl A., Enderle F., Saitner M., Manzke A., Pfahler C., Wiedemann S., Ziemann P. Non-close-packed crystals from self-assembled polystyrene spheres by isotropic Plasma etching: Adding flexibility to colloid lithography. Adv. Funct. Mater. 2009, 19, 3279–3284.
Ji D. Y., Wang Y. D., Chi L. F., Fuchs H. Enhanced charge injection through nanostructured electrodes for organic field effect transistors. Adv. Funct. Mater. 2015, 25, 3855–3859.
Yin J., Zang Y. S., Yue C., Wu Z. M., Wu S. T., Li J., Wu Z. H. Ag nanoparticle/ZnO hollow nanosphere arrays: Large scale synthesis and surface plasmon resonance effect induced Raman scattering enhancement. J. Mater. Chem. 2012, 22, 7902–7909.
Li J. F., Huang Y. F., Ding Y., Yang Z. L., Li S. B., Zhou X. S., Fan F. R., Zhang W., Zhou Z. Y., Wu D. Y., et al. Shell-isolated nanoparticle-enhanced Raman spectroscopy. Nature 2010, 464, 392–395.
Li J. F., Zhang Y. J., Ding S. Y., Panneerselvam R., Tian Z. Q. Core-shell nanoparticle-enhanced raman spectroscopy. Chem. Rev. 2017, 117, 5002–5069.
Liu G. Q., Li X. H., Wang W. B., Zhou F., Duan G. T., Li Y., Xu Z. K., Cai W. P. Gold binary-structured arrays based on monolayer colloidal crystals and their optical properties. Small 2014, 10, 2374–2381.
Wendisch F. J., Oberreiter R., Salihovic M., Elsaesser M. S., Bourret G. R. Confined etching within 2D and 3D colloidal crystals for tunable nanostructured templates: Local environment matters. ACS Appl. Mater. Interfaces 2017, 9, 3931–3939.
Liu Y. S., Luo F. Spatial Raman mapping investigation of SERS performance related to localized surface plasmons. Nano Res. 2020, 13, 138–144.
Natan M. J. Concluding remarks-Surface enhanced Raman scattering. Faraday Discuss. 2006, 132, 321–328.
Wang Y. D., Zhang M. Y., Feng L., Dong B., Xu T., Li D., Jiang L., Chi L. F. Tape-imprinted hierarchical lotus seedpod-like arrays for extraordinary surface-enhanced Raman spectroscopy. Small 2019, 15, 1804527.
Oh Y. J., Jeong K. H. Glass Nanopillar arrays with nanogap-rich silver nanoislands for highly intense surface enhanced Raman scattering. Adv. Mater. 2012, 24, 2234–2237.
Wang X. Z., Wang Z., Zhang M., Jiang X. S., Wang Y. F., Lv J. G., He G., Sun Z. Q. Three-dimensional hierarchical anatase@rutile TiO2 nanotree array films decorated by silver nanoparticles as ultrasensitive recyclable surface-enhanced Raman scattering substrates. J. Alloys Compd. 2017, 725, 1166–1174.
Cai W. B., Ren B., Li X. Q., She C. X., Liu F. M., Cai X. W., Tian Z. Q. Investigation of surface-enhanced Raman scattering from platinum electrodes using a confocal Raman microscope: Dependence of surface roughening pretreatment. Surf. Sci. 1998, 406, 9–22.
Ingram W. M., Han C. Q., Zhang Q. J., Zhao Y. P. Optimization of Ag-coated polystyrene nanosphere substrates for quantitative surface-enhanced Raman spectroscopy analysis. J. Phys. Chem. C 2015, 119, 27639–27648.
Liu B. H., Han G. M., Zhang Z. P., Liu R. Y., Jiang C. L., Wang S. H., Han M. Y. Shell thickness-dependent Raman enhancement for rapid identification and detection of pesticide residues at fruit peels. Analy. Chem. 2012, 84, 255–261.
Acknowledgment
This work was supported by the National Natural Science Foundation of China (Nos. 51821002 and 21790053) and the China Postdoctoral Science Foundation (No. 2016M591908).
Author information
Authors and Affiliations
Corresponding authors
Electronic supplementary material
Rights and permissions
About this article
Cite this article
Chen, Y., Li, H., Chen, J. et al. Self-generating nanogaps for highly effective surface-enhanced Raman spectroscopy. Nano Res. 15, 3496–3503 (2022). https://doi.org/10.1007/s12274-021-3924-8
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12274-021-3924-8