Strategies to Realize AC Electrokinetic Enhanced Mass‐Transfer in Silicon Based Photonic Biosensors.

Abstract Silicon‐on‐insulator (SOI) based photonic sensors, particularly those utilizing Photonic Integrated Circuit (PIC) technology, have emerged as promising candidates for miniaturized bioanalytical devices. These sensors offer real‐time responses, occupy minimal space, possess high sensitivity, and facilitate label‐free detection. However, like many biosensors, they face challenges when detecting analytes at exceedingly low concentrations due to limitations in mass transport. An intriguing method to enhance mass transfer in microfluidic biosensors is AC electrokinetics. Proof‐of‐concept experiments have demonstrated significant enhancements in limit of detection (LOD) and response times. AC electrokinetics, compatible with silicon photonic sensors, offers techniques such as electroosmosis, electrothermal effects, and dielectrophoresis to modify fluid flow and manipulate particle trajections. This article delves into various approaches for integrating AC electrokinetics into silicon photonic biosensors, shedding light on both its advantages and limitations.