Micro/nano-fabrication technology via two-photon polymerization (TPP) nanolithography is a powerful and useful manufacturing tool that is capable of generating two dimensional (2D) to three dimensional (3D) arbitrary micro/nano-structures of various materials with a high spatial resolution. This technology has received tremendous interest in cell and tissue engineering and medical microdevices because of its remarkable fabrication capability for sophisticated structures from macro- to nano-scale, which are difficult to be achieved by traditional methods with limited microarchitecture controllability. To fabricate precisely designed 3D micro/nano-structures for biomedical applications via TPP nanolithography, the use of photoinitiators (PIs) and photoresists needs to be considered comprehensively and systematically. In this review, widely used commercially available PIs are first discussed, followed by elucidating synthesis strategies of water-soluble initiators for biomedical applications. In addition to the conventional photoresists, the distinctive properties of customized stimulus-responsive photoresists are discussed. Finally, current limitations and challenges in the material and fabrication aspects and an outlook for future prospects of TPP for biomedical applications based on different biocompatible photosensitive composites are discussed comprehensively. In all, this review provides a basic understanding of TPP technology and important roles of PIs and photoresists for fabricating high-precision stimulus-responsive micro/nano-structures for a wide range of biomedical applications.
ZnCdHgSe quantum dots (QDs) functionalized with N-acetyl-l-cysteine were synthesized and characterized. Through layer-by-layer assembling, the ZnCdHgSe QDs was integrated with a polymerized 1-decyl-3-[3-pyrrole-1-yl-propyl]imidazolium tetrafluoroborate (PDPIT) ionic liquid film modified indium tin oxide (ITO) electrode to fabricated a photoelectrochemical interface for the immobilization of rabbit antihuman neuron specific enolase (anti-NSE). After being treated with glutaraldehyde vapor and bovine serum albumin successively, an anti-NSE/ZnCdHgSe QDs/PDPIT/ITO sensing platform was established. Simplely using a white-light LED as an excitation source, the immunoassay of neuron specific enolase (NSE) was achieved through monitoring the photocurrent variation. The polymerized ionic liquid film was demonstrated to be an important element to enhance the photocurrent response of ZnCdHgSe QDs. The anti-NSE/ZnCdHgSe QDs/PDPIT/ITO based immunosensor presents excellent performances in neuron specific enolase determination. The photocurrent variation before and after being interacted with NSE exhibits a good linear relationship with the logarithm of its concentration (log cNSE) in the range from 1.0 pg mL(-1) to 100 ng mL(-1). The limit of detection of this immunosensor is able to reach 0.2 pg mL(-1) (S/N = 3). The determination of NSE in clinical human sera was also demonstrated using anti-NSE/ZnCdHgSe QDs/PDPIT/ITO electrode. The results were found comparable with those obtained by using enzyme-linked immunosorbent assay method.
Light-responsive liquid crystal elastomers (LCEs) are one kind of attractive and fascinating materials in developing untethered and dexterous bioinspired robotic systems. Unlike widely explored azobenzene-containing LCE actuators utilizing photoisomerization, near-infrared...
Silanization processes with perfluoroalkyl silanes have been demonstrated
to be effective in developing advanced materials with many functional
properties, including hydrophobicity, water repellency, and self-cleaning
properties. However, practical industrial applications of perfluoroalkyl
silanes are limited by their extremely high cost. On the basis of
our recent work on photoredox catalysis for amidation with perfluoroalkyl
iodides, its application for surface chemical modification on filter
paper, as an illustrative example, has been developed and evaluated.
Before photocatalytic amidation, the surface is functionalized with
amine functional groups by silanization with 3-(trimethoxysilyl)propylamine.
All chemically modified surfaces have been fully characterized by
attenuated total reflection infrared (ATR-IR), X-ray photoelectron
spectroscopy (XPS), scanning electron microscopy with energy-dispersive
spectroscopy (SEM-EDS), and three-dimensional (3D) profiling to confirm
the successful silanization and photocatalytic amidation. After surface
modification of the filter papers with perfluoroalkanamide, they show
high water repellency and hydrophobicity with contact angles over
120°. These filter papers possess high wetting selectivity, which
can be used to effectively separate the organic and aqueous biphasic
mixtures. The perfluoroalkanamide-modified filter papers can be used
for separating organic/aqueous biphasic mixtures over many cycles
without lowering the separating efficiency, indicating their reusability
and excellent durability.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.