Facile one-pot synthesis of folic acid-modified graphene to improve the performance of graphene-based sensing strategy.

A convenient and environment-friendly method is reported to synthesize the reduced graphene oxide (rGO) sheets in aqueous solution using folic acid (FA) as both a reducing and stabilizing agent, to improve the performance of graphene-based sensing strategy. The as-prepared FA-rGO sheets were characterized by transmission electron microscopy (TEM), UV-vis absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA), which provided the clear identification of the removal of oxygen-containing functional groups from the graphene oxide (GO) to form FA-rGO sheets. Further, it was found that the obtained FA-rGO sheets exhibited better biocompatibility and could act as the more efficient energy acceptor in long range resonance energy transfer (LrRET) process than that of graphene.

One-pot hydrothermal synthesis of orange fluorescent silver nanoclusters as a general probe for sulfides.

Water-soluble fluorescent silver nanoclusters (AgNCs) with almost seven and nine silver atoms and a quantum yield (QY) of 5.38 ± 0.25% were successfully prepared via one-pot hydrothermal synthesis using polymethacrylic acid sodium salt (PMAA-Na) as a template.

Highly selective colorimetric detection of spermine in biosamples on basis of the non-crosslinking aggregation of ssDNA-capped gold nanoparticles.

The selective adsorption of single-stranded oligonucleotides (ssDNA) on gold nanoparticles (AuNPs) is well known for stabilizing the AuNPs against aggregation even at high salt concentrations. Our investigation shows that the non-crosslinking aggregation of arbitrary ssDNA-capped AuNPs occurs due to their interaction with the cationic polyamine, spermine (Spm), even without any addition of NaCl. The non-crosslinking aggregation mechanism is that the Spm, served as multivalent counterions, plays the dual roles of charge shielding and ion bridging among the ssDNA-capped AuNPs, which jointly result in the aggregation of the ssDNA-capped AuNPs.

Obstruction of photoinduced electron transfer from excited porphyrin to graphene oxide: a fluorescence turn-on sensing platform for iron (III) ions.

A comparative research of the assembly of different porphyrin molecules on graphene oxide (GO) and reduced graphene oxide (RGO) was carried out, respectively. Despite the cationic porphyrin molecules can be assembled onto the surfaces of graphene sheets, including GO and RGO, to form complexes through electrostatic and π-π stacking interactions, the more obvious fluorescence quenching and the larger red-shift of the Soret band of porphyrin molecule in RGO-bound states were observed than those in GO-bound states, due to the difference of molecular flattening in degree. Further, more interesting finding was that the complexes formed between cationic porphyrin and GO, rather than RGO sheets, can facilitate the incorporation of iron (III) ions into the porphyrin moieties, due to the presence of the oxygen-contained groups at the basal plane of GO sheets served as auxiliary coordination units, which can high-efficiently obstruct the electron transfer from excited porphyrin to GO sheets and result in the occurrence of fluorescence restoration.

Calf thymus DNA-stabilized polythiophene fluorescence probe for label-free detection of spermine.

It is a challenge to detect molecules lacking a chromophore, such as polyamines, by optical methods since they are insensitive to light. In order to detect the optical signals, it is compulsory to derive these molecules with optical labels, which, however, is complicated, time-consuming and may be expensive. In this work, a highly specific strategy for spermine detection is developed on the basis of the iodide-induced conformational change of polythiophene.

Carbon nanotube-DNA hybrid used for activity monitoring and inhibitor screening of nuclease.

Carbon nanotubes (CNTs) can efficiently quench the fluorescence of the adsorbed fluorophores and nonconvalently interact with soft single-stranded DNA (ssDNA). Upon disruption of CNTs-fluorescent oligonucleotides hybrid by nuclease S1, fluorescence turn-on was observed. Using this strategy, a platform based on fluorescence signal for monitoring the activity of nuclease with advantages of high sensitivity and commonality was established, and a linear relationship between initial cleavage reaction rate and nuclease S1 concentration is found in the range of 0.

Highly selective detection of phosphate in very complicated matrixes with an off-on fluorescent probe of europium-adjusted carbon dots.

A simple method for phosphate (Pi) detection is established by developing an off-on fluorescence probe of europium-adjusted carbon dots (CDs), which has been successfully applied to the detection of Pi in very complicated matrixes such as artificial wetlands system.

A localized surface plasmon resonance light-scattering assay of mercury (II) on the basis of Hg(2+)-DNA complex induced aggregation of gold nanoparticles.

It is known that localized surface plasmon resonance (LSPR) is responsible for the surface-enhanced spectroscopic processes of metallic nanoparticles and thus LSPR spectroscopy has become a powerful technique for chemical and biological purposes. In this contribution, we present a simple homogeneous Hg2+ assay by measuring enhanced LSPR scattering signals resulted from Hg(2+)-DNA complex induced aggregation of gold nanoparticles (AuNPs). In a medium of pH 7.

Light scattering sensing detection of pathogens based on the molecular recognition of immunoglobulin with cell wall-associated protein A.

In this contribution, we report a rapid optical detection method of pathogens using Staphylococcus aureus (S. aureus) as the model analyte based on the molecular recognition of immunoglobulin with cell wall-associated Protein A (SpA). It was found that the molecular recognition of human immunoglobulin (IgG) with protein A on the cell wall of S.

Enhanced plasmon resonance light scattering signals of colloidal gold resulted from its interactions with organic small molecules using captopril as an example.

Gold nanoparticles are known for their plasmon resonance absorption (PRA) depending on their size. Our this investigation shows that plasma resonance light scattering (PRLS) signals in the corresponding PRA region could be measured using a common spectrofluorometer, and be enhanced when aggregation of gold nanoparticles occurs due to their interaction with organic small molecules (OSMs). Using captopril (Cap) as an example, we investigated the interactions of gold nanoparticles with OSMs in order to propose a general method of OSMs such as typical clinic organic drugs.

Increased inflammatory factors activity in model rats with experimental autoimmune prostatitis.

Male rats were immunized with prostate tissue homogenate supernate (PTHS) of male rats with complete Freund's adjuvant (CFA) intra dermal in the multiple points and simultaneously immunized with 0.5 ml Pertussis-Diphtheria-Tetanus (PDT) vaccine intra peritonea on 0 and 30th day. At the 45th day after first immunization, animals were sacrificed and a series of examinations such as HE stain, assay of TNF-alpha by ELISA and assay of inducible nitric oxide synthase (iNOS) mRNA by in-situ hybridization (ISH) were taken.

[Morphological and molecular biological peculiarities of the experimental autoimmune prostatitis rat model].

Objective: To observe the morphological and molecular biological peculiarities of the experimental autoimmune prostatitis (EAP) rat model made by SC purified prostate protein twice with immune adjuvant.

Methods: Male rats were intradermally immunized with a saline extract of male rat prostate glands (RPG) in Freund's complete adjuvant (FCA) and Pertussis-Diphtheria-Tetanus vaccine 0.5 ml i.