Microneedle‐based transdermal electrochemical biosensors based on Prussian blue‐gold nanohybrid modified screen‐printed electrodes

Abstract

We report on the fabrication of a microneedle-based electrochemical biosensor for use in transdermal biosensing, which includes a screen-printed electrode containing a Prussian blue-gold nanohybrid as the working electrode. The Prussian blue gold nanohybrid is made from polyethylenime (PEI)-mediated simultaneous synthesis of Prussian blue (PBNP) and gold nanoparticles (AuNP), which forms a PBNP-AuNP nanohybrid with a remarkable change in the Prussian blue character. PEI-protected polycrystalline PBNPs can be synthesized in acidic media from the single precursor potassium ferricyanide [K 3 Fe(CN) 6 ] at 60 C. Since PEI also enables the controlled formation of gold nanoparticles (AuNPs) in the presence of formaldehyde, nanohybrids containing PBNPs and AuNPs may be prepared. Two different methods of PEI mediated synthesis of AuNP in the presence of PBNP were considered. In Method 1, AuNP and PBNP were made independently and mixed together in an appropriate ratio. In Method 2, PBNPs were made first, followed by PEI-and formaldehyde-mediated reduction of gold cations in the presence of PBNP. PBNP-AuNPs display a remarkable change in Prussian blue behavior such that the absorption maxima of PBNP-AuNPs made through Method 1 tend to increase at 670 nm as a function of gold concentration as compared with the control; the reverse was observed when PBNP-AuNPs were made through Method 2. As made PBNPs and PBNP-AuNPs made through Method 1 display excellent catalytic activity toward both reduction and oxidation of hydrogen peroxide based on peroxidase mimetic activity. In addition, the as-synthesized PBNPs displayed superparamagnetic behavior that can be manipulated in the presence of AuNPs. The results from peroxidase mimetic activity, chemiluminescence, cyclic voltammetry, and amperometry showed suitable analytical performance of the as-made PBNP-AuNP nanohybrid for biomedical applications.

A skin patch integrating swellable microneedles and electrochemical test strips for glucose and alcohol measurement in skin interstitial fluid

“…Ribet et al imbedded a full three‐electrode strip in the lumen of a single hollow silicon MN 27 . The test strip could also adhere to hollow 28,29 or porous MNs 15 elements through resin encapsulation and designed chamber. In these designs, hollow and porous MNs extracted skin fluid through capillary force without changing the shape of MNs, therefore these strategies for integrating MNs and test strips were not suitable for MNs made from materials with good swelling properties including but not limited to MeHA.…”

Biofabricating hollow microneedle array with controllable microstructure for cell transplantation

“…This is sufficient for uses in potential cell therapy to treat vitiligo, which requires melanocytes restoration in the basal epidermis approximately a depth of 200 μm. Similarly, alopecia requires dermal papilla cells located at the upper dermis approximately at a depth of 500 μm to regulate hair regeneration and pigmentation 21,22 …”

Recent Progress in Microneedles‐Mediated Diagnosis, Therapy, and Theranostic Systems

“…[ 36–39 ] MNs can penetrate in the skin and create microchannels for sampling and directly biosensing the biomarker molecules in the ISF. [ 40–44 ] Thus, current MNs‐based transdermal diagnosis systems can be classified as: in vivo sampling of analytes in ISF and follow‐up in vitro testing [ 45–47 ] and in vivo capture and detection of analytes in ISF. [ 48–51 ] The latter shows an obvious advantage in the aspect of turn‐round time and simplification.…”

“…According to the drug release mechanisms of free diffusion, active driven by external force, and self‐regulation in responsive with surrounding environments, MNs‐assisted transdermal delivery strategies can be divided into passive release, active release, and responsive release, respectively. [ 17,31–66 ] Compared with the oral and intravenous routes, MNs‐assisted drug delivery has several advantages, including minimally invasive self‐administration and improved patient compliance.…”