# Solvent-Assisted Modification of Laser-Induced Graphene for Surface-Enhanced Electrochemical Response

## TL;DR

This paper shows that treating laser-induced graphene with DMSO improves its electrochemical performance, making it more effective for sensing applications.

## Contribution

The study demonstrates that solvent treatment, specifically with DMSO, can significantly enhance the electrochemical properties of laser-induced graphene.

## Key findings

- DMSO treatment increases the electrochemical activity of LIG electrodes by modifying surface properties.
- The treatment improves wettability and reduces structural defects in LIG, enhancing π–π stacking.
- DMSO-treated LIG successfully detected sulfanilamide in synthetic urine and water with high sensitivity.

## Abstract

The fabrication and
application of laser-induced graphene (LIG)
have received significant interest across various research fields,
particularly in sensing technologies. Herein, we investigated the
surface modification of LIG electrodes with different solvents and
demonstrated that dimethyl sulfoxide (DMSO) enhances their electrochemical
activity. Importantly, our findings reveal that solvent treatments
themselves can induce significant modifications on the electrode surface
(e.g., changes in functional groups, wettability, and morphology),
which must be carefully considered in sensor design and optimization.
The application of a microliter aliquot of DMSO to the LIG surface
significantly altered its wettability, promoting a transition to hydrophilic
behavior, which was verified by contact-angle measurements. AFM and
XRD results indicate that DMSO treatment promotes the rearrangement
of disordered carbon atoms, minimizing localized structural defects
and enabling more efficient π–π stacking between
graphene sheets. The cyclic voltammetric response of the [Fe­(CN)6]3‑/4‑ redox probe showed a 3-fold
increase in peak current. The enhanced electrochemical effect of DMSO
surface changes on LIG electrodes was also confirmed in the presence
of several organic species, and a substantial current increase was
verified by the effect of DMSO. As proof-of-concept, the antibiotic
sulfanilamide was detected in synthetic urine and water samples using
differential-pulse voltammetry on DMSO-treated LIG. Under optimized
conditions, the sensor exhibited a linear response in the range of
0.3–9.0 μmol L–1 with a limit of detection
of 0.09 μmol L–1 and satisfactory recovery
values (90–104%).