Bioinspired Polydopamine Modification for Interface Compatibility of PDMS-Based Responsive Structurally Colored Textiles.

Textiles that can repeatedly change color in the presence of external stimuli have attracted great interest. Effectively designing to produce such functional textiles is essential, yet there remain challenges like producing stable coloration, rapid response, and reverse color changing. Here, the preparation of a magnetic field response (MFR) textile with a fast magnetic field response, brilliant structural coloration, and mechanical robustness is reported. The MFR textile is knitted by incorporating magnetic particles' ethylene glycol (EG) suspension within polydimethylsiloxane (PDMS)-based fibers. A surface modification strategy is designed to prevent EG from seeping out along the PDMS polymer chains. A PDMS fiber is encapsulated in waterborne polyurethane, and a polydopamine joint layer is used. The MFR textile demonstrates magnetic field-triggered structural colors, and the breaking strength and elongation at break of each composite fiber are improved. In addition, multishaped patterns can be printed on the MFR textile with the help of the photo etching technology, which enhances the applications of the new functional textiles.

Photonic crystal sensor for melamine based on magnetic molecularly imprinted nanoparticles self-assembled with an amphiphilic random copolymer.

Magnetic molecularly imprinted nanoparticles (MMINPs) were obtained with a one-step process through miniemulsion self-assembly using an amphiphilic random copolymer as both an emulsifier and MMINP coating, oleic acid-modified magnetite nanoparticles as magnetic cores, and melamine (MEL) as the template molecule. MMINPs were assembled under an external magnetic field to construct photonic crystal (PC) sensor for naked-eye detection of MEL. The MMINPs were characterized by FT-IR, TEM, TGA, and VSM. The analytical performances of the magnetic molecularly imprinted PC sensor for MEL (MEL-MMIPCs) were investigated with respect to sensitivity, response time, selectivity, and stability. As the MEL concentration increases from 1.0 to 1.0 × 106 µg/l, the reflection wavelength of MEL-MMIPCs shifted from 497 to 709 nm, and was linear with the logarithm of MEL concentration in this range. The detection limit was 0.21 µg/l (S/N = 3) and response time was within 30 s. The MEL-MMIPC sensor had an imprinting factor of 5.09, and selectivity factors for the analogs cyanuric acid and atrazine were 8.76 and 5.75, respectively, indicating the high sensitivity and selectivity. After 10 cycles of elution/response, MEL-MMIPCs still had a good ability to recognize MEL.

A self-healing smart photonic crystal hydrogel sensor for glucose and related saccharides.

A self-healing smart PhC hydrogel sensor that combines the optical property of photonic crystal and the dynamic regeneration property of boronate ester bond has been prepared for determination of glucose and related saccharides using Debye diffraction ring detection. The boronate ester bond formed through phenylboronic acid and dopamine endows the hydrogel network self-healing ability, and the tensile stress of the healing hydrogel can recover to 94.4%; this excellent self-healing property can effectively improve the reliability and lifetime of the hydrogel. Due to the high bonding capacity between 1,2- and 1,3-diol and phenylboronic acid, the hydrogel sensor has a good recognition ability for glucose and related saccharides. The reaction between the monosaccharides and the phenylboronic acid group makes the sensor swell and the diameter of the Debye diffraction ring decrease. The sensor shows good reuse and responsive ability for saccharides; the RSD of the recoverability assays is 4.3%. The determination range of the sensor to glucose is 0.5 to 12 mM. The sensor also has good response to glucose in urine, exhibiting potential application value in the preliminary screening of diabetes. Although the sensor has poor selectivity for specific monosaccharides, the process of measuring the Debye ring makes the determination no longer rely on expensive and complicated equipment and greatly simplifies the determining process and reduces the cost of determination, which shows a broad application prospect. The boronate ester bond formed through phenylboronic acid and dopamine results in the self-healing property of hydrogel network, which can effectively improve the reliability and lifetime of hydrogel. And due to the high bonding capacity between 1,2- and 1,3-diol and phenylboronic acid, the smart hydrogel sensor has a good recognition ability for glucose and related saccharides. The reaction between the monosaccharides and the phenylboronic acid group breaks the original boronate ester bond; this will lead to a decrease in cross-linking density of the PhC hydrogel sensor and further makes the sensor swell and the diameter of the Debye diffraction ring decrease.

Facile fabrication of magnetically responsive PDMS fiber for camouflage.

A new type of photonic crystal PDMS fiber which exhibits tunable structural color upon exposure to external magnetic field is described in this article. The novel magnetic field responsive fiber was prepared from embedding ethylene glycol droplets (containing Fe3O4@C nanoparticles) into PDMS. In the presence of an external magnetic field, Fe3O4@C nanoparticles which dispersed in ethylene glycol droplets formed one dimensional chain-like structures along the magnetic field. As a result, the color of the fiber changes to yellow green. By contrast, when the magnetic field was removed, the color of the fiber will disappear and display its original color. Moreover, this novel PDMS fiber has good mechanical properties and could keep its color under a fixed magnetic field no matter it was stretched or squeezed. This study is expected to have some important applications such as none-powered and functionalized fibers for camouflage.

Specific and ultrasensitive ciprofloxacin detection by responsive photonic crystal sensor.

A new approach for specific and ultrasensitive measurement of ciprofloxacin has been developed by integrating ternary complexes into responsive photonic crystal (RPC). Tryptophan was first immobilized within the polyacrylamide hydrogel substrates of RPC. The determination of ciprofloxacin was via the existence of zinc(II) ions that function as a 'bridge' to form specific tryptophan-zinc(II)-ciprofloxacin complexes step by step, which resulted in a stepwise red-shift of the diffraction wavelength. A maximum wavelength shift from 798 to 870 nm for ciprofloxacin was observed when the RPC film was immersed in 10(-4)M ciprofloxacin. A linear relationship has been obtained between the Δλ of diffraction peak and logarithm of ciprofloxacin concentration at pH 5.0 in the range of 10(-10) to 10(-4)M. And the least detectable concentration in present work is about 5 × 10(-11)M. The results demonstrated that the as-designed ternary complexes-based RPC sensor exhibited high sensitivity, satisfactory specificity and excellent recoverability for sensing of ciprofloxacin in aqueous media and were validated by detecting ciprofloxacin in the eye-drop sample.