Nanophotonic devices, which control light in subwavelength volumes and enhance light-matter interactions, have opened up exciting prospects for biosensing. Numerous nanophotonic biosensors have emerged to address the limitations of the current bioanalytical methods in terms of sensitivity, throughput, ease-of-use and miniaturization. In this Review, we provide an overview of the recent developments of label-free nanophotonic biosensors using evanescent-field-based sensing with plasmon resonances in metals and Mie resonances in dielectrics. We highlight the prospects of achieving an improved sensor performance and added functionalities by leveraging nanostructures and on-chip and optoelectronic integration, as well as microfluidics, biochemistry and data science toolkits. We also discuss open challenges in nanophotonic biosensing, such as reducing the overall cost and handling of complex biological samples, and provide an outlook for future opportunities to improve these technologies and thereby increase their impact in terms of improving health and safety.

Chair in Hybrid Nanosystems Nanoinstitut Munich Faculty of Physics Ludwig Maximilians Universität München Munich Germany

Department of Electrical and Computer Engineering University of Minnesota Minneapolis MN USA

Department of Physics Imperial College London London UK

Institute of Photonics and Electronics of the Czech Academy of Sciences Prague Czech Republic

Laboratory of Bionanophotonic Systems Institute of Bioengineering École Polytechnique Fédérale de Lausanne Lausanne Switzerland

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