Surface modification and construction of LAPS towards biosensing applications

The light-addressable potentiometric sensor (LAPS) is a spatially resolved biochemical sensor based on a field-effect structure. Over the past three decades, it has gained significant attention for the detection of various ions, biomolecules (e.g. enzymes, antibodies, DNA, and biomarkers), cellular metabolic activities as well as neuronal action potentials. To improve the sensor function and performance, all of these applications rely on the physical or chemical modifications of LAPS with different transducer materials and/or bio(chemical) recognition elements. With the rapid development of biomaterials associated with new sensing and fabrication techniques, remarkable advances in LAPS design, fabrication and applications have been achieved. In this review, the features and fabrication technologies of different gate insulators of LAPS are illustrated. Especially, ultrathin insulators such as organic monolayers are highlighted. The state-of-the-art technologies for LAPS modification and construction as well as their consequent applications in chemical and biological fields are summarized and discussed. Finally, current research challenges and future prospectives, for instance the combination of LAPS with microfluidic chips, will be presented.