Dual-Mode Electro-Optical Techniques for Biosensing Applications: A Review

Abstract

The monitoring of biomolecular interactions is a key requirement for the study of complex biological processes and the diagnosis of disease. Technologies that are capable of providing label-free, real-time insight into these interactions are of great value for the scientific and clinical communities. Greater understanding of biomolecular interactions alongside increased detection accuracy can be achieved using technology that can provide parallel information about multiple parameters of a single biomolecular process. For example, electro-optical techniques combine optical and electrochemical information to provide more accurate and detailed measurements that provide unique insights into molecular structure and function. Here, we present a comparison of the main methods for electro-optical biosensing, namely, electrochemical surface plasmon resonance (EC-SPR), electrochemical optical waveguide lightmode spectroscopy (EC-OWLS), and the recently reported silicon-based electrophotonic approach. The comparison considers different application spaces, such as the detection of low concentrations of biomolecules, integration, the tailoring of light-matter interaction for the understanding of biomolecular processes, and 2D imaging of biointeractions on a surface.

Electrochemical biosensors for pathogen detection

“…Electrochemical-surface plasmon resonance (EC-SPR) combines SPR sensing capability based on binding-induced refractive index changes at the electrode-electrolyte interface with electrochemical sensing capability on the same electrode (Hu et al 2008). This approach has been used for monitoring molecular binding events (Juan-Colas et al 2017) and could potentially be applied to selective detection of pathogens.…”

Critical assessment of relevant methods in the field of biosensors with direct optical detection based on fibers and waveguides using plasmonic, resonance, and interference effects

“…It is stated that OWLS is superior to QCM. Interesting is the combination of OWLS and electrochemistry to monitor the adsorbed mass of charged molecules and to study the reversibility of a adsorption processes [258].…”

Study on Combined Optical and Electrochemical Analysis Using Indium‐tin‐oxide‐coated Optical Fiber Sensor

“…Possibilities for multi‐domain sensing, which may include simultaneous, e. g., optical, electrical or mechanical interrogation, has been intensively explored in the last decade . Study in additional domains may enhance information about the investigated sample or provide confirmation of results received in the other domain.…”

“…Thin ITO films have similarly been applied for combined optical and EC analysis on planar and optical fiber sensing devices, but in this case ITO was applied mainly in order to initialize EC‐induced polymerization of a compound necessary for further detection procedure . Meanwhile, it has been found that when the potential is applied to the electrode in opto‐EC setup and both optical and EC responses are investigated simultaneously, significantly more information can be received about the investigated medium than when the responses are studied separately .…”