Biofunctionalization of Multiplexed Silicon Photonic Biosensors

Abstract

Silicon photonic (SiP) sensors offer a promising platform for robust and low-cost decentralized diagnostics due to their high scalability, low limit of detection, and ability to integrate multiple sensors for multiplexed analyte detection. Their CMOS-compatible fabrication enables chip-scale miniaturization, high scalability, and low-cost mass production. Sensitive, specific detection with silicon photonic sensors is afforded through biofunctionalization of the sensor surface; consequently, this functionalization chemistry is inextricably linked to sensor performance. In this review, we first highlight the biofunctionalization needs for SiP biosensors, including sensitivity, specificity, cost, shelf-stability, and replicability and establish a set of performance criteria. We then benchmark biofunctionalization strategies for SiP biosensors against these criteria, organizing the review around three key aspects: bioreceptor selection, immobilization strategies, and patterning techniques. First, we evaluate bioreceptors, including antibodies, aptamers, nucleic acid probes, molecularly imprinted polymers, peptides, glycans, and lectins. We then compare adsorption, bioaffinity, and covalent chemistries for immobilizing bioreceptors on SiP surfaces. Finally, we compare biopatterning techniques for spatially controlling and multiplexing the biofunctionalization of SiP sensors, including microcontact printing, pin- and pipette-based spotting, microfluidic patterning in channels, inkjet printing, and microfluidic probes.

Repeatable Passive Fiber Optic Coupling of Single-Mode Waveguides in High-Precision Disposable Photonic Biosensors

“…Future work will investigate the feasibility of transitioning to an automated assembly process for the sensor chips, moving away from the current manual methods. The integration of the system with microfluidics [31,34] and the surface functionalization of the MRR sensors with capture molecules [17] will be pursued to enable selective sensing capabilities.…”

“…This field enables the quantitative measurement of, for example, aqueous solution concentrations, by detecting shifts in the MRR resonance wavelength λres caused by changes in the refractive indices on the sensor surface [16]. Additionally, this relative measurement method allows for the qualitative detection of targeted binding events if the sensor is appropriately functionalized [17]. Further details regarding the used sensor concept can be found in [10].…”

Recent Progress in Functional-Nucleic-Acid-Based Fluorescent Fiber-Optic Evanescent Wave Biosensors

“…Please note that this review does not include SPR- or silicon-photonic-based FOEW biosensors. In those biosensors, the detection of targets is achieved by measuring the refractive index changes, instead of fluorescence intensity changes [ 19 , 20 , 21 ].…”

High‐Resolution 2D Quasi‐Distributed Optical Sensing with On‐Chip Multiplexed FSR‐Free Nanobeam Cavity Array

“…Additionally, multiplexed functionalization with different bioreceptors allows for the simultaneous detection of multiple analytes from a single sample. [16] Although arrayed waveguide grating (AWG) has achieved many physical channels, [17,18] it suffers from large device sizes and the inflexibility to independently control each channel. On the other hand, whispering gallery mode (WGM) cavities such as micro-ring/disk are compact and fundamentally provide resonant enhancement modulation/sensing, along with the inherent capability for wavelength multiplexing.…”

“…Additionally, multiplexed functionalization with different bioreceptors allows for the simultaneous detection of multiple analytes from a single sample. [ 16 ]…”