Erythropoietin (EPO) is an attractive protein-unfolding/folding model because of its high degree of unfolding and folding reversibility and intermediate size. Due to its function for regulating red blood cell production by stimulating late erythroid precursor cells, EPO presents obvious values to biological research. A nonemissive anthracene derivative, that is 9,10-bis[4-(3-sulfonatopropoxyl)-styryl]anthracene sodium salt (BSPSA), with aggregation-induced emission (AIE) charateristics shows a novel phenomenon of AIE when EPO is added. The AIE biosensor for EPO shows the limit of detection is 1 × 10(-9) M. Utilizing the AIE feature of BSPSA, the unfolding process of EPO using guanidine hydrochloride is monitored, which indicates three steps for the folding structures of EPO to transform to random coil. Computational modeling suggests that the BSPSA luminogens prefer docking in the hydrophobic cavity in the EPO folding structures, and the assembly of BSPSA in this cavity makes the AIE available, making the monitoring of unfolding of EPO possible.

Hierarchical CdS spherical aggregates have been fabricated by an assembling strategy starting from nanoparticles, which opens a general way to obtain hierarchical spherical aggregates of different types of materials. The hierarchical CdS spherical aggregates are of high porosity and high surface area, which give rise to unique photoluminescence properties. The desirable properties we report here will spur further developments of novel dopamine photoluminescence sensors based on the high surface area hierarchical CdS spherical aggregates fabricated with our unique assembling strategy. The novel dopamine photoluminescence sensor has a low detection limit of1.0×10−8 M, which is much lower than those reported previously.

This paper describes the applications of multifunctional magnetic nanoparticles (MNPs) for the enrichment of low-abundance proteins for polyacrylamide gel electrophoresis (PAGE) separation. The hemoglobin-functionalized MNPs, named Hb-MNPs, were obtained based on electrostatic interactions and covalent binding between the hemoglobin (Hb) and the MNPs. It was demonstrated that the proteins in human serum were selectively conjugated to Hb-MNPs, which can be used for the selective enrichment of low-abundance proteins. Three and seven kinds of proteins were identified by MS after 1-D and 2-D PAGE, respectively. Comparing with native PAGE without the treatment of MNPs, some proteins were observed, such as human serum amyloid P component (SAP), vitamin D-binding protein, and serine peptidase inhibitor. Because the high concentration of SAP can be considered as a signal for the neurodegeneration of Alzheimer's disease, the present Hb-MNPs-based method was applied to investigate the serum level of SAP for the diagnosis of Alzheimer's disease, and the results are satisfying.

The ELSD response for HSA was enhanced by using GNPs, making it possible to determine HSA by ELSD.

A method for the determination of different polar flavonoids from multiflora fruit by reverse-phase high-performance liquid chromatography (HPLC) is presented in this article. Chromatographic separation of these flavonoids was performed over a Diamonsil C 18 column (200 mm  4.6 mm  5 mm) using gradient elution with an isopropanol-methanol-water mixture at 25 C, at a flow rate ranging from 0.5 to 1.5 mL=min and detection at 360 nm. The flavonoids could be separated within 6 min; the recovery was between 96% and 104%, and the relative standard deviation was 1.6-2.6%. This method allows rapid detection of flavonoids.