Revolutionizing biosensing with superwettability: Designs, mechanisms, and applications

Interfacial superwettability and biosensors are constantly evolving and being recognized as ubiquitous components of interfacial science. Superwettability provides new insight from micro/nano scale to revolutionize the study of biosensors to improve the sensitivity, selectivity, accuracy, and practicality in clinical diagnosis and environmental monitoring. However, these superwettability-boosted biosensors require complex design and rigorous optimization of parameters due to the variation in surface topography and modulation of surface recognition. To reduce the confusion and barriers to entry in controlled tailoring of the interfacial superwettability of biosensors, this review presents an overview of the fundamental understanding of superwettability, and the classification of superwettable biosensors, which can be divided into homogeneous and heterogeneous superwettable biosensor. The biosensing mechanisms based on superwettable surfaces are reviewed in detail, including stimuli-responsive superwetting mechanism, droplet evaporation-enhanced enrichment mechanism, and liquid phase-regulated sensing mechanism. The emerging applications, such as nucleic acid analysis, immunoassay, single-cell trapping, bacteria-related study, and wearable electronics, are highlighted. The limitations and potential research viewpoints in superwettable biosensors are also discussed. By introducing the state-of-the-art of this important and rapidly expanding area, this review will motivate industrial circles and multidisciplinary scientific communities to create superwettable biosensors that can fulfil the demands of different practical applications.