# Laser-Induced Graphene Dual Optical/Electrochemical Platform for In-Chip Sensing Applications

## TL;DR

This paper introduces a new sensor made from laser-induced graphene that can detect substances using both light and electrical signals, potentially improving portable diagnostic devices.

## Contribution

The novelty lies in combining optical and electrochemical sensing in a single laser-induced graphene-based platform for point-of-care applications.

## Key findings

- The sensor's performance was tested using ferrocyanide and a model dye, showing its dual sensing capabilities.
- The study demonstrated simultaneous optical and electrochemical detection of ferrocyanide electro-oxidation.
- Laser exposure parameters were found to influence the sensor's morphology and electrical properties.

## Abstract

The present study addresses the development and characterization of an in-chip laser-induced graphene (LIG)-based sensor that combines optical and electrochemical transduction techniques as a proof of concept for the advancement of novel point-of-care (POC) devices. In recent years, LIG has emerged as a suitable material for next-generation diagnostic devices due to the increasing need for effective and easily accessible biosensing platforms. In this context, the presented sensors were fabricated and tested with an increasing number of laser exposures to understand how the resulting morphology, degree of graphitization, defects, and electrical resistance of LIG electrodes affect the electrochemical and optical sensing performance. To validate the dual sensor, ferrocyanide ([Fe(CN)6]4−) was used as a redox probe and [(4-Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran] (DCM) was used as model dye to explore the electrochemical and optical sensing capabilities. Finally, we showcase the sensor’s ability to perform simultaneous optical and electrochemical on-time detection and analysis of the ferrocyanide electro-oxidation process, underscoring its potential to be used as a dual optical/electrochemical POC device.