abstract
Zinc oxide (ZnO)/laser-induced graphene (LIG) composites were prepared by mixing ZnO, grown by laser-assisted flow deposition, with LIG produced by laser irradiation of a polyimide, both in ambient conditions. Different ZnO:LIG ratios were used to infer the effect of this combination on the overall composite behavior. The optical properties, assessed by photoluminescence (PL), showed an intensity increase of the excitonic-related recombination with increasing LIG amounts, along with a reduction in the visible emission band. Charge-transfer processes between the two materials are proposed to justify these variations. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy evidenced increased electron transfer kinetics and an electrochemically active area with the amount of LIG incorporated in the composites. As the composites were designed to be used as transducer platforms in biosensing devices, their ability to detect and quantify hydrogen peroxide (H2O2) was assessed by both PL and CV analysis. The results demonstrated that both methods can be employed for sensing, displaying slightly distinct operation ranges that allow extending the detection range by combining both transduction approaches. Moreover, limits of detection as low as 0.11 mM were calculated in a tested concentration range from 0.8 to 32.7 mM, in line with the values required for their potential application in biosensors.
keywords
HYDROGEN-PEROXIDE; ZINC-OXIDE; CARBON NANOTUBES; RAMAN-SPECTROSCOPY; GLUCOSE SENSOR; LAYER GRAPHENE; QUANTUM DOTS; LABEL-FREE; ONE-STEP; ZNO
subject category
Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation
authors
Zanoni, J; Moura, JP; Santos, NF; Carvalho, AF; Fernandes, AJS; Monteiro, T; Costa, FM; Pereira, SO; Rodrigues, J
our authors
Alexandre Faia Carvalho
Post-Doc Fellowship
Nuno Miguel Franco dos Santos
PhD Student
Sónia Oliveira Pereira
Research FellowshipGroups
acknowledgements
This research was funded by national funds through the FCT-Portuguese Foundation for Science and Technology under the i3N project UIDB/50025/2020 & UIDP/50025/2020. Funds were also received from FCT/MEC and FEDER, through the COMPETE 2020 Program, under project PTDC/NAN-MAT/28755/2017 (POCI-01-0145-FEDER-028755). The APC was funded by the project PTDC/NAN-MAT/28755/2017.