Modification-free pumpless laser-induced graphene multichannel open microfluidic electrode chip for simultaneous quantification of dual targets

Abstract

Pumpless surface fluid transport technology has attracted concerns in the field of electroanalysis. However, the combination of surface wettability-controlled multichannel fluid transport and flexible three-electrode systems has been rarely reported for electrochemical detection. Here, we have developed a modification-free pumpless laser-induced graphene multichannel open microfluidic electrode chip (LIG-MOMEC) for simultaneous quantification of dual targets. The LIG-MOMEC enables rapid sample distribution to four addressable locations for multiple parallel tests on a single chip and simultaneous detection of dopamine (DA) and uric acid (UA) using differential pulsed voltammetry. The flexible polyimide templated by laser parameters supports a programmable electrochemical sensing surface with desired conductivity and optimal surface wettability without post-chemical modification, effectively avoiding the tedious multi-step processing and time-consuming surface modification of conventional modified electrodes. The LIG-MOMEC has a linear detection range of 0.91 ∼ 171.15 μM for DA and 0.83 ∼ 250.04 μM for UA with the LODs of 72 nM and 48 nM. Due to the advantages of superior selectivity, anti-interference and reliable stability, the LIG-MOMEC could be reversibly used 30 times with high reproducibility and attain satisfactory recovery in human serum samples. The LIG-MOMEC provides great potential for the rapid detection of biomolecules in clinical diagnostics and biochemical analysis.