3D NiO nanoflakes/carbon fiber meshwork: Facile preparation and utilization as general platform for photocathodic bioanalysis.

Herein, we describe a customized approach for facile preparation of three-dimensional (3D) NiO nanoflakes (NFs)/carbon fiber meshwork (CFM) and its validation as a common photocathode matrix for photoelectrochemical (PEC) bioanalysis, which to our knowledge has not been reported. Specifically, 3D NiO NFs/CFM was fabricated by a sequential liquid phase deposition and annealing process, which was then characterized by scanning electron microscopy, X-ray photoelectron spectrum, UV-vis absorption spectra and N2 adsorption-desorption measurement. Sensitized by BiOI and incorporated with an alkaline phosphatase (ALP)/tyrosinase (TYR) bi-enzyme cascade system, a sensitive split-type cathodic PEC bioanalysis for the determination of ALP was achieved. This method can detect ALP concentrations down to 3 × 10-5 U L-1 with a linear response range of 0.001-10 U L-1. Moreover, this proposed system exhibited good selectivity, stability and excellent performance for real sample analysis. This research features the facile preparation of 3D NiO NFs/CFM that could acts as a universal matrix for photocathodic analysis, and is envisioned to stimulate more effort for advanced 3D photocathode for PEC bioanalysis and beyond.

Enhanced organic-inorganic heterojunction of polypyrrole@Bi2WO6: Fabrication and application for sensitive photoelectrochemical immunoassay of creatine kinase-MB.

In this report, enhanced organic-inorganic heterojunction of polypyrrole@Bi2WO6 was fabricated and applied for sensitive photoelectrochemical (PEC) immunoassay of creatine kinase-MB (CK-MB). Specifically, heterostructured polypyrrole@Bi2WO6 photoelectrode was prepared and sandwich immunorecognition were integrated for the CK-MB immunoassay. In the detection, with the aid of alkaline phosphate (ALP)-induced biocatalytic precipitation (BCP), the precipitation-dependent suppression of the photocurrent can be recorded due to the impediment of the interfacial mass and electron transfer. On the basis of target-controlled BCP formation, a novel PEC immunoassay could be developed for the sensitive and specific CK-MB detection. This work manifested the great potential of polypyrrole@Bi2WO6 heterojunction as a novel platform for PEC bioanalysis development and also a PEC method for CK-MB detection. This work is expected to stimulate more interest in the design and implementation of numerous other organic-inorganic heterojunction for advanced PEC bioanalysis development.

Glucose microfluidic biosensors based on reversible enzyme immobilization on photopatterned stimuli-responsive polymer.

In this paper, we demonstrate a new strategy for replaceable enzymatic microreactor based on a switchable wettability interface of poly(N-isopropylacrylamide) (PNIPAAm). PNIPAAm porous polymer monolith (PPM) with 3D macroporous framework is photopolymerized in glass microchip within 30 s. The PNIPAAm PPM not only shows its reversible swelling/shrinking property at the different temperature around the lower critical solution temperature (LCST), but also shows reversible hydrophilicity/hydrophobicity corresponding to its swelling/shrinking status. Based on these properties, a biocompatible and replaceable on-chip enzymatic microreactor has been successfully built by means of the reversible adsorption and release of glucose oxidase (GOx) on the robust and stable matrix. Coupled with a carbon fiber microelectrode as electrochemical detector, the microreactor has been successfully employed for detection of glucose with a linear range from 0.05 to 5 mM. This approach may provide a promising way for high efficient and renewable microreactors that will find wide application in clinical diagnosis, biochemical synthesis/analysis, and proteomic research.

Glass etching to bridge micro- and nanofluidics.

In this study, a simple and economical fabrication technique bridging micro- and nanostructures is proposed. Glass molds with micro-nanostructures are fabricated by glass microlithography. The microlithography provides flexibility for structure design, and the glass etching contributes to transform the micro glass ridge to the nanoscale. Glass ridge structures with triangular cross sections are generated by undercutting, which coupled the isotropic character of glass and the shield effect of the top Cr layer upon HF etching. Further etching induced the height of the glass ridges to shrink from micro- to nanometres due to the edge effects. At the late etching stage, the geometrical change of the glass greatly slows down, which gives better control over the size of the glass ridge. By glass structure mold-copy, well repeatable, mechanically stable and tunable polydimethylsiloxane (PDMS) channels and cones are fabricated. Scanning electron microscopy (SEM) and laser interferometry (LI) are carried out to characterize the micro-nanostructures. To demonstrate their workability, sample preconcentration to a single nanochannel level is carried out.

[Study on needling depth and direction from different acupoints to sphenopalatine ganglion].

OBJECTIVE: To observe and survey the location of Xiaguan (ST 7), "Die'e" and Quanliao (SI 18) on the surface, and the needling depth and direction from the 3 points to sphenopalatine ganglion. METHODS: Fifteen corpses (30 sides) of adult male were fixed by 10% formalin. The lateral areas of face were dissected from the surface to the deep on the 3 acupoints: the electric drill with the kirschner wire punctured towards the sphenopalatine ganglion and extended to the contralateral areas according to different directions of puncturing sphenopalatine ganglion from the 3 acupoints. The corresponding puncturing points of the 3 acupoints were measured by the coordinate location method. RESULTS: (1) Surface location: the distance between Quanliao (SI 18) and "Die'e" was 21 mm and the distance between Xiaguan (ST 7) and "Die'e" was 17 mm; (2) Inserting depth of each point to sphenopalatine ganglion: the depths of Xiaguan (ST 7), "Die'e" and Quanliao (SI 18) were 49.9 mm, 46.9 mm and 46.6 mm, respectively; (3) The coordinate location of the corresponding puncturing points: the puncturing direction of Xiaguan (ST 7) was anterointernal upper corresponding to the area of connecting center between contralateral Taiyang (EX-HN 5) and Tongziliao (GB 1), the distance between the corresponding inserting point of Xiaguan (ST 7) and Sizhukong (TE 23) was 17.6 mm; the puncturing direction of "Die'e" point was posterointernal upper, and the horizontal distance from the corresponding puncture point to the zygomatic arch was 33 mm and the vertical distance from the corresponding puncture point to the eyes' outer canthus was 42 mm; the puncturing direction of Quanliao (SI 18) was posteriointernal upper and the distance between the corresponding inserting point and the area of contralateral parietal tuber, the distance between the corresponding inserting point of Quanliao (SI 18) and the connecting line of bilateral external acoustic pore was 28 mm, the distance between the corresponding inserting point of Quan-liao (SI 18) and the medial line of the head was 62 mm. CONCLUSION: Understanding the surface location, inserting depths and the general puncturing directions of the 3 points can provide basis for puncturing the sphenopalatine ganglion in clinical practice.