Molecularly Imprinted Polymer Grafted Porous Au‐Paper Electrode for an Microfluidic Electro‐Analytical Origami Device

Abstract

Molecular imprinting technique is introduced into microfluidic paper‐based analytical devices (μ‐PADs) through electropolymerization of molecular imprinted polymer (MIP) in a novel Au nanoparticle (AuNP) modified paper working electrode (Au‐PWE). This is fabricated through the growth of a AuNP layer on the surfaces of cellulose fibers in the PWE. Due to the porous morphology of paper as well as the high specific surface area and conductivity of the resulting AuNP layer on the cellulose fibers, the effective surface area and the sensitivity of the Au‐PWE is enhanced remarkably. Based on this novel MIP‐Au‐PWE and the principle of origami, a microfluidic MIP‐based electro‐analytical origami device (μ‐MEOD), comprised of one auxiliary pad surrounded by four sample tabs, is developed for the detection of D‐glutamic acid in a linear range from 1.2 nM to 125.0 nM with a low detection limit of 0.2 nM. The selectivity, reproducibility, and stability of this μ‐MEOD are investigated. This μ‐MEOD would provide a new platform for high‐throughput, sensitive, specific, and multiplex assay as well as point‐of‐care diagnosis in public health, environmental monitoring, and the developing world.

Self‐Powered and Sensitive DNA Detection in a Three‐Dimensional Origami‐Based Biofuel Cell Based on a Porous Pt‐Paper Cathode

“…It could be seen that there was no apparent structural and surface difference between the bare (Figure 1 A) and the AuNP-seeded (Figure 1 B) or PtNP-seeded (Figure 1 C) cellulose fibers in the paper hydrophilic zone of paper electrode due to the small particle size of AuNP and PtNP seeds. According to our previous work, [34][35][36] after 10 min of growth, a continuous and dense conducting AuNPs layer with interconnected Au NPs was obtained completely on the cellulose fiber surfaces (Figure 1 D).…”

“…The growth process of the PtNPs layer on the surfaces of cellulose fibers was tracked by SEM characterization (Figure 2). As the growth time increased (from 0 to 10 min), the PtNP seeds were rapidly enlarged by incubating in the growth solution under the self‐catalytic reduction mechanism of PtNP growth (Figure 2 A and B) 35. Finally, a continuous and dense conducting PtNPs layer with interconnected PtNPs was obtained completely on the cellulose fiber surfaces after 15 min of growth (Figure 2 C and D).…”

Multifunctional Molecularly Imprinted Receptor-Based Polymeric Membrane Potentiometric Sensor for Sensitive Detection of Bisphenol A

“…As illustrated, there is almost no redox peak on the CV curve for the conventional MIP receptor (line b in Figure ). This can be ascribed to the insulating properties of the conventional MIP which fully blocks the electron-transfer reaction of [Fe­(CN) 6 ] 3–/4– . , In contrast, the CV of the multifunctional MIP at GCE surface shows a pair of large and reversible redox peaks of [Fe­(CN) 6 ] 3–/4– (line a in Figure ). A difference between the anodic and cathodic potentials is estimated to be 0.12 V. These results suggest that the integration of conducting poly­(aniline) into the insulating MIP is effective for the improvement of the electron-transfer kinetics of the electrochemical reaction of [Fe­(CN) 6 ] 3–/4– .…”

Supramolecular Modulator Assisted Cryo‐Engineered Porous Cu‐DNA Nano‐Vehicles for Versatile Theranostic Agent Delivery

“…It exhibits both photothermal and photodynamic effects to achieve cytotoxicity under near‐infrared (NIR) irradiation. [ 18 ] However, individually‐administered ICG has limitations including concentration‐dependent aggregation, poor water stability, and rapid body clearance. [ 19 ] Encapsulating ICG into carriers providing enhanced stability, prolonged circulation, and protection from nonspecific plasma protein binding represents a hopeful strategy.…”