Refractive index sensing with electrochemical sensor

Introduction Fast, reliable and cheap sensors for biomarker detection have the potential of enabling early diagnosis of severe conditions. Here, a nano-structured optical/electrochemical sensor is presented as a basis for... [ view full abstract ]

Introduction
Fast, reliable and cheap sensors for biomarker detection have the potential of enabling early diagnosis of severe conditions. Here, a nano-structured optical/electrochemical sensor is presented as a basis for highly specific biomolecule detection. Hole-mask colloidal lithography allow for rapid large-area patterning of sensor surface with plasmonic gold-nanodisks, which function as interface for both optical and electrochemical sensing of analytes.

Methods
Gold-structured sensor surface was fabricated on indium-doped zinc oxide-coated glass by hole-mask colloidal lithography. A home-made electrochemical flow cell was used for optical/electrochemical proof-of-concept measurements.

Results
Sensor is able to reliably detect changes in bulk refractive index of less than 0.015, as well as electrochemical reduction of ferricyanide.

Discussion
By simultaneously measuring different properties of an analyte, multifunctional sensors have the potential of improving fidelity of measurements and provide a means of recognizing false positive detection events.
Presented is a proof-of-concept system that is not specific to any particular analyte. Specificity can be achieved by functionalizing the sensor surface with antibodies or molecular imprinted polymers.