Development and evaluation of mild TBI rapid diagnostic strips based on GFAP labeled with quantum dots / 军事医学

Objective To establish an auxiliary method for diagnosis of mild traumatic brain injury based on serum GFAP rapid detection test strips using immunochromatographic technology labeled with quantum dot microspheres.Methods The quantum dot microspheres were coupled with GFAP antibodies.The detection conditions were optimized to obtain the fluorescence probe in order to prepare the immunochromatographic test strips.An auxiliary diagnostic method was established after optimization of detection conditions.Finally,the auxiliary diagnostic effect of the test strips was evaluated using clinical samples.Results The serum concentration of GFAP could be detected by the optimized test strips within 13 mins with a detection limit of 0.15 ng/mL,and no more than 70μL of the serum sample was required.In addition,good reproducibility was achieved by different batches of test strips(CV=10.7%).The detection sensitivity and specificity of the strips to mild traumatic brain injury using 51 clinical samples were 95.24%and 96.67%respectively,indicating good effects of detection.Conclusion The developed test strips are user-friendly with reliable results,which can facilitate field rapid diagnosis of mild traumatic brain injury in complicated wartime environments.

Establishment and Preliminary Application Analysis of A Multiplex Detection Method for Influenza A and B Virus Antigen Based on Quantum Dot-encoded Microsphere Flow Cytometry Technology / 现代检验医学杂志

Objective To establish a multiplex assay method for the simultaneous detection of FluA and FluB virus(IBV)antigen based on the flow cytometry(FCM)quantum dot-encoded bead technologies,laying the foundation for the assay of multiple respiratory virus biomarkers.Methods Coupling was performed for FluA and FluB nucleoprotein(NP)monoclonal antibodies using self-made quantum dot-encoded beads,separately.FCM was used to detect known concentrations of FluA and FluB antigens separately and simultaneously,optimize the detection conditions,and establish a joint detection method for FluA and FluB antigens.Compared with the quantitative real-time PCR(qPCR)method,clinical samples were used to evaluate the clinical performance of this joint detection method.Results The joint detection method for FluA and FluB antigens was established,with detection limits of 26.1 pg/ml and 10.7 pg/ml,respectively,and measurement ranges of 15.3～250 000 pg/ml.The joint detection method for clinical sample evaluation was well correlated with the qPCR,with a positive coincidence rate of 57.4%,a negative coincidence rate of 100%,and a total coincidence rate of 71.6%.In addition,the joint detection method was superior to colloidal gold immunochromatographic strip assay commonly used in clinical practice(positive coincidence rate of 56.49%,negative coincidence rate of 99.75%).Conclusion The FCM quantum dot-encoded bead multiplex assay can be used for the joint detection of FluA and FluB antigens,which have a high sensitivity,good specificity and wide detection range.It may lay a good foundation for the multiplex detection of common respiratory viruses,and has clinical application prospects.

Mechanism of black phosphorus regulating oxidative stress-inflammation cascade in retarding intervertebral disc degeneration / 中国组织工程研究

BACKGROUND:Oxidative stress plays a critical role in intervertebral disc degeneration.As a reducing material with good biocompatibility,black phosphorus quantum dots have the potential to resist oxidative stress and retard intervertebral disc degeneration.OBJECTIVE:To evaluate the effect of black phosphorus quantum dots on scavenging reactive oxygen species in the microenvironment of an intervertebral disc through in vivo and in vitro experiments,and further explore the role of black phosphorus quantum dots in Nrf2/ARE pathway and intervertebral disc inflammation.METHODS:Black phosphorus quantum dots were prepared by a liquid exfoliation technique.(1)In vitro experiment:The nucleus pulposus cells of SD rats were isolated and extracted,and the passages 2-4 nucleus pulposus cells were cocultured with different solutions,including F12-DMEM medium(blank group),black phosphorus quantum dot solution,hydrogen peroxide solution,hydrogen peroxide+black phosphorus quantum dot solution,hydrogen peroxide+black phosphorus quantum dot+Nrf2 specific inhibitor ML385 solution.Cell live/dead staining and intracellular reactive oxygen species,mitochondrial membrane potential and western blot assay were performed respectively.(2)In vivo experiment:Thirty SD rats were randomly divided into sham operation,puncture and puncture + black phosphorus groups,with 10 rats in each group.A Co7-10 intervertebral disc degeneration model was established using intervertebral disc puncture in the puncture group and the puncture+black phosphorus group.Black phosphorus quantum dot solution was injected in the intervertebral disc after a puncture in the puncture+black phosphorus group.The intervertebral disc tissue imaging and histological staining were evaluated at 4 and 8 weeks after surgery.RESULTS AND CONCLUSION:(1)In vitro experiment:Live/dead staining revealed that the black phosphorus quantum dots had good biocompatibility,were non-toxic to cells,and had a protective effect on nucleus pulposus cells under oxidative stress.Intracellular reactive oxygen species and JC-1 fluorescent probes showed that black phosphorus quantum dots could regulate the reduction of mitochondrial membrane potential caused by oxidative stress in nucleus pulposus cells and protected cells from hydrogen peroxidation-induced intracellular oxidative stress.Western blot analysis showed that compared with the blank group,the protein expressions of Nrf2,heme oxygenase 1,quinone oxidoreductase and type Ⅱ collagen were decreased in the hydrogen peroxide group(P<0.05),while the protein expressions of tumor necrosis factor α,interleukin 1β,matrix metalloproteinase 13 and p65 were increased(P<0.05).The addition of black phosphorus quantum dots could reverse the inhibitory effect of hydrogen peroxide on the Nrf2 pathway and reduce the inflammatory response caused by oxidative stress,but NrF2-specific inhibitors could cancel this effect.(2)In vivo experiment:X-ray and MRI demonstrated that at 4 and 8 weeks after surgery,the intervertebral disc height and water content of nucleus pulposus in the puncture group were lower than those in the sham operation group(P<0.05),and the intervertebral disc height and water content of nucleus pulposus in the puncture+black phosphorus group were higher than those in the puncture group(P<0.05).Histological staining exhibited that the degree of intervertebral disc degeneration in the puncture+black phosphorus group was less than that in the puncture group,and the expression of heme oxygenase 1 protein was higher than that in the puncture+black phosphorus group.(3)Our results have indicated that black phosphorus quantum dots can exert an antioxidant effect and delay intervertebral disc degeneration by regulating Nrf2/ARE pathway.

Bionic optic nerve based on perovskite (CsPbBr 3) quantum-dots / 生物医学工程学杂志

The bionic optic nerve can mimic human visual physiology and is a future treatment for visual disorders. Photosynaptic devices could respond to light stimuli and mimic normal optic nerve function. By modifying (Poly(3,4-ethylenedioxythio-phene):poly (styrenesulfonate)) active layers with all-inorganic perovskite quantum dots, with an aqueous solution as the dielectric layer in this paper, we developed a photosynaptic device based on an organic electrochemical transistor (OECT). The optical switching response time of OECT was 3.7 s. To improve the optical response of the device, a 365 nm, 300 mW·cm -2 UV light source was used. Basic synaptic behaviors such as postsynaptic currents (0.225 mA) at a light pulse duration of 4 s and double pulse facilitation at a light pulse duration of 1 s and pulse interval of 1 s were simulated. By changing the way light stimulates, for example, by adjusting the intensity of the light pulses from 180 to 540 mW·cm -2, the duration from 1 to 20 s, and the number of light pulses from 1 to 20, the postsynaptic currents were increased by 0.350 mA, 0.420 mA, and 0.466 mA, respectively. As such, we realized the effective shift from short-term synaptic plasticity (100 s recovery of initial value) to long-term synaptic plasticity (84.3% of 250 s decay maximum). This optical synapse has a high potential for simulating the human optic nerve.

Recent advances in quantum dots-based biosensors for antibiotics detection / 药物分析学报

Antibiotics are a category of chemical compounds used to treat bacterial infections and are widely applied in cultivation,animal husbandry,aquaculture,and pharmacy.Currently,residual antibiotics and their metabolites pose a potential risk of allergic reactions,bacterial resistance,and increased cancer incidence.Residual antibiotics and the resulting bacterial antibiotic resistance have been recognized as a global challenge that has attracted increasing attention.Therefore,monitoring antibiotics is a critical way to limit the ecological risks from antibiotic pollution.Accordingly,it is desirable to devise new analytical platforms to achieve efficient antibiotic detection with excellent sensitivity and specificity.Quantum dots(QDs)are regarded as an ideal material for use in the development of antibiotic detection biosensors.In this review,we characterize different types of QDs,such as silicon,chalcogenide,carbon,and other doped QDs,and summarize the trends in QD-based antibiotic detection.QD-based sensing applications are classified according to their recognition strategies,including molecularly imprinted polymers(MIPs),aptamers,and immunosensors.We discuss the advantages of QD-derived antibiotic sensors,including low cost,good sensitivity,excellent stability,and fast response,and illustrate the current challenges in this field.

Lead sulfide quantum dots for the near-infrared IIb window fluorescence imaging of colon cancer / 药学学报

The near-infrared-IIb (NIR-IIb, 1 500-1 700 nm) window fluorescence with long emission wavelength has reduced light scattering and tissue auto-fluorescent background, achieving deep tissue imaging with high spatial resolution. Herein, we prepared an NIR-IIb fluorescent quantum dots (QDs) composed of lead sulfide (PbS). The fluorescence spectrum of PbS QDs were adjusted by controlling the size of the PbS core. Cadmium sulfide (CdS) shell was synthesized by the cation exchange method to form the core/shelled lead sulfide/cadmium sulfide quantum dots (CSQDs). The surface of CSQDs was modified with polyethylene glycol (PEG) to increase their stability in aqueous solution. The resulting PEG-modified CSQDs (PEG-CSQDs) had the emission peak at ~1 550 nm with quantum yield of 7.2%. The animal procedures were approved by the Institutional Animal Care and Use Committee (IACUC) of Fudan University School of Pharmacy. At 2 h postinjection, PEG-CSQDs clearly delineated the tumor region of mice bearing orthotopic CT26-Luc colon cancer model in the NIR-IIb fluorescence imaging. The fluorescent intensity ratio of primary tumor and adjacent normal tissue was 42.3, and that of metastatic tumor and adjacent normal tissue was 22.3, which allowed to detect the primary tumor of 3.4 mm×2.5 mm in dimension and the metastatic tumor of 1.2 mm×0.9 mm in dimension, and accurately guided the excision of tumors. The PEG-CSQDs prepared in this study provided a new approach for the early diagnosis and guidance of surgical resection of colon cancer.

Intravenous transplantation of olfactory ensheathing cells at different time points for repairing spinal cord injury / 中国组织工程研究

BACKGROUND: Olfactory ensheathing cells promote axonal regeneration, provide nutritional support for the injured host cells and regulate inflammation reaction, which possess potential for spinal cord injury repair. OBJECTIVE: To explore the optimal time window for intravenous transplantation of olfactory ensheathing cells in the treatment of spinal cord injury. METHODS: Thirty male SPF level rats were used to establish the rat models of spinal cord injury by spinal cord hemisection. Rat models were then randomly divided into five groups: 1-, 3-, 7-and 10-day olfactory ensheathing cell transplantation and PBS groups. Olfactory ensheathing cells were labeled with fluorescent quantum dots. PBS was injected into the rats in the PBS group after spinal cord injury. The injured spinal cord was removed at 1 day after injection. A small animal imager was used to measure the fluorescence transferred to the lesion at different time points. The number of cells transferred to the lesion was measured based on the intensity of fluorescence. The Anti-p75 NGF Receptor antibody was used for immunohistochemistry detection of the injured spinal cord. The study was approved by the Ethics Committee of Animal Laboratory of Ningxia Medical University, No. 2017-073. RESULTS AND CONCLUSION: Fluorescent quantum dots could label olfactory ensheathing cells. Results of fluorescence assay and immunohistochemistry indicated that transplanted olfactory ensheathing cells were transferred to the lesion at 1, 3, 7 and 10 days. Most cells were transferred to the lesion at 7 days. Therefore, these results indicate that olfactory ensheathing cells transplanted at different time points after spinal cord injury can be transferred to the lesion, with a number peak at 7 days that is the best time window for cell transplantation.

In vitro study of black phosphorus quantum dot-loaded liposomes for photothermal therapy of cervical cancer / 药学学报

In this study, black phosphorus quantum dots (BPQDs)-loaded liposomes (liposome-BPQDs) were prepared to explore physicochemical properties and photothermal effects on cervical cancer cells. BPQDs were fabricated by ultrasonic method. Liposome-BPQDs were prepared by thin film dispersion. Surface morphology, particle size, zeta potential and Raman spectra of liposome-BPQDs were characterized. The cytotoxicity of the liposome-BPQDs against human cervical cancer cells (HeLa) was examined by CCK-8 assay. Confocal laser scanning microscope (CLSM) and fluorescence microscopy were used to observe the uptake and apoptosis of HeLa cells. The results indicated that liposome-BPQDs were ellipsoidal or spherical under scanning electron microscope, TEM observation showed liposome-BPQDs were about 90-110 nm in diameter. The particle size measurements showed liposome-BPQDs were (104.2±0.35) nm in diameter, and zeta potential were examined to be (-11.3±3.01) mV. The encapsulation efficiency was (84.40±2.13)%.Under natural conditions with outdoor ventilation, temperature range of 25 ℃-34 ℃ and relative humidity of 80%-82%, the photothermal effects of liposome-BPQDs was better and the degradation denaturation of liposome-BPQDs were slower than those of BPQDs. The results also reflected that liposome-BPQDs could be uptaken by HeLa cells easily. After near-infrared laser irradiation, the mortality of HeLa cells rise significantly when the amount of BPQDs reach 20 μg·mL-1. In summary, liposome-BPQDs with high stability exhibited good photothermal effects, which can be expected to be applied to photothermal therapy of cervical carcinoma.

The black phosphorus quantum dots-based photothermal effect on dendritic cells activation / 药学学报

Immunotherapy is the most active research area for cancer treatment. Tumor vaccine is one of the most developed aspects of cancer immunotherapy. Though tumor vaccine has made many breakthrough, it still faces many challenges. In this study, we coated the black phosphorus quantum dots (BPQDs) with cancer cell membrane to create a nanoparticle named BPQD-CCNVs. The BPQD-CCNVs were incubated with bone marrow-derived dendritic cells and irradiated with 808 nm infrared light. We tested the expression level of CD80, CD86 and MHC II of dendritic cells by flow cytometry after irradiation. All animal experiments approved by the Animal Experiments Ethical Committee of Tsinghua University. The results showed that the rise of medium's temperature caused by the photothermal effect of BPQDs could upregulate the expression of CD80, CD86 and MHC-II on dendritic cell surface. Based on these, we conclude that near infrared irradiation can stimulate the activation of dendritic cells. Our study may have provided a new strategy for tumor vaccine development.

Preparation and <italic>in vitro</italic> evaluation of phospholipid-coated silver-graphene quantum dot multifunctional nanoparticles / 药学学报

@#In this paper, multifunctional silver-graphene quantum dot nanoparticles coated with phospholipids (ADG-DDPC) were prepared and their properties were evaluated <italic>in vitro</italic>. Cationic phospholipids 1,2-diolefinoxy-3-trimethy-laminopropane (DOTAP) was absorbed first onto the surface of the core of silver nanoparticle (AgNPs) through the mutual attraction between the positive and negative charge. Based on the principle of phase transformation and hydrophobic interaction, dstearyl-phosphatidylglycolamine-polyethylene-glycol-cyclic-cRGD peptide (DSPE-PEG₂₀₀₀-cRGD) self-assembled onto the outlayer of DOTAP of AgNPs. A stable multifunctional nano-preparation was formed and its ultraviolet absorption, particle size distribution, morphology,<italic>in vitro</italic> release behavior, ability to kill cancer cells and cell uptake were studied. The maximum UV absorption of the synthesized nanometer preparation was about 400 nm. Malvern particle size meter and transmission electron microscope showed that the particle size of the nano- preparation was about 30-40 nm and its particle size distribution was uniform. The <italic>in vitro</italic> release of nano-preparation was positively correlated with the concentration of H₂O₂. The IC₅₀ value of AgNPs for tumor cells was (347.78 ± 0.06) ng·mL^-1, and the IC₅₀ value of ADG-DDPC for tumor cells was (209.68 ± 0.09) ng·mL^-1, indicating that ADG-DDPC possessed a stronger cytotoxicity than that of AgNPs. Cell uptake experiment showed that ADG-DDPC could be absorbed by tumor cells and exhibited fluoresce inside those cells. In conclusion, ADG-DDPC was successfully prepared, and <italic>in vitro</italic>characterization study pointed to that the nano-preparation exhibits a higher antitumor activity than AgNPs.

Black phosphrous quantum dot (BPQD)-loaded erythrocyte membrane vesicles for phothothermal therapy in breast cancer / 国际生物医学工程杂志

Objective To investigate the method of preparing black phosphrous quantum dot (BPQD)-loaded erythrocyte membrane nanovesicles (BPQD-EMNVs), and to study its efficiency in photothermal therapy for breast cancer. Methods Fresh red blood cells (RBCs) of healthy mice were extracted to prepare erythrocyte membrane, and BPQD-EMNVs were prepared by sonication method. The morphology of BPQD-EMNVs was observed by a transmission electron microscopy. The particle size distribution was measured by a nano-particle size and Zeta potential meter. The encapsulation efficiency of BPQD was determined by inductively coupled plasma emission spectrometry. The uptake rate of BPQD-EMNVs was observed by a laser scanning confocal microscope. 4T1 tumor-bearing Balb/c mice were randomly divided into PBS, EMNVs, BPQD and BPQD-EMNVs groups, and the tumor sites were irradiated with 808 nm near-infrared light for 10 min after 4 hours of tail vein injection. The growth of the tumors was continually observed. Results The prepared BPQD-EMNVs have a regular spherical shape with an average particle diameter of 228 nm and an encapsulation efficiency of about 47％. Cellular uptake in vitro experiments showed that BPQD-EMNVs were rapidly taken up by 4T1 tumor cells. The results of animal in vivo experiments showed that BPQD-EMNVs had the highest enrichment after 4 h of injection at the tumor site, and BPQD-EMNVs could effectively kill tumor tissues after 10 min of 808 nm near-infrared light irradiation. Conclusions The BPQD-EMNVs are easy to prepare, and the prepared nanovesicles have good biocompatibility and photothermiotherapy effect, which is expected to be a promising method for breast cancer therapy.

Vancomycin-based fluorescent enzyme-linked immunoabsorbent assay for detection of Staphylococcus aureus / 生物工程学报

In the study, fluorescent enzyme-linked immnoabsorbent assay for detection of Staphylococcus aureus was established with IgG from pig as capture antibody and quantum dot nanobeads (QBs) labeled vancomycin (QB-Vans) as testing antibody. Quantum dot of about 100 nm partical size nanobeads were prepared and linked with vancomycin. The optimum concentrations of salt ions were 0.01 mol/L, and the optimum pH was 6.0. Under the optimum conditions, the detection sensitivity for S. aureus was 10⁴ CFU/mL, and there was no cross-reaction with other pathogenic bacteria. Thus, the method could be used for rapid screening of S. aureus, for the clinical monitoring and foodborne pathogens detection.

Detection of procalcitonin based on fluorescence immune chromatography / 生物工程学报

Procalcitonin (PCT) is the precursor of calcitonin related to the severity of human bacterial infection. We made a test strip by coupling anti-PCT to quantum dot, in order to develop a highly sensitive and convenient PCT testing product. The anti-PCT titer had reached 10⁷ because of the stability by coupling anti-PCT with quantum dot. The detecting linear range of the experiment was 0.15 to 120 μg/L, the sensitivity was 0.007 μg/L, the recovery range was 91% to 113%, and the intra- and inter-assay coefficient of variation was less than 8%. Comparing the homemade fluorescence-detected test strip with PCT ELISA kit on sale, we got accurate results which could mostly accomplish the test of clinical samples.

Molybdenum Disulfide Quantum Dots-based Fluorescence Sensor for Detection of Doxycycline Hyclate / 分析化学

Molybdenum disulfide ( MoS2) quantum dots ( QDs) were synthesized using one-step hydrothermal method with an acceptable fluorescence property. Based on the quenching effect between doxycycline hyclate ( DOX) and MoS2QDs, a fluorescence method for detection of DOX was established. The interaction between MoS2QDs and DOX was discussed with a final proposal of the static quenching mechanism. A good linear correlation for detection of DOX using fluorescenct MoS2QDs was obtained in the concentration range of 0. 86-55. 40 μg/mL, with a detection limit of 0. 023 μg/mL (S/N=3). The fabricated sensor was applied to the detection of DOX in real samples with RSDs of less than 5% . The relative error of determination results of MoS2QDs method compared with HPLC was from -4. 5% to 0. 8% and -4. 6% to 2. 8% for DOX tablet and DOX spiked milk, respectively. The fluorescence detection of DOX in real sample using MoS2QDs was simple, rapid and reliable.

Effect of 3-MPA coated CdSe-CdS/ZnS quantum dots on the uptake, proliferation and migration of human umbilical vein endothelial cells / 国际生物医学工程杂志

Objective To explore the effects of 3-mercaptopropionic acid (3-MPA) coated CdSe-CdS/ZnS quantum dots (3-MPA-QDs) on the uptake , proliferation and migration of human umbilical vein endothelial cells (HUVEC), and to study the biotoxicity of 3-MPA-QDs, so as to provide the theoretical basis for the development of quantum dot photosensitizers . Methods The short-term ( 6 h ) uptakes of 3-MPA-QDs and the small molecule photosensitizer protoporphyrin IX (PpIX) in HUVEC cells were real-time observed and compared by a laser confocal scanning microscope. Besides, the uptakes within 48 h as well as the effects of the uptake on morphology and proliferation of HUVEC were also observed. The effect of 3-MPA-QDs on the migration of HUVEC cells within 24 h was observed using a grid dish. LysoTrackerTM Deep Red was used to label lysosomes, and the endocytosis mechanism of 3-MPA-QDs was observed by fluorescence co-localization. Results The fluorescence of 3-MPA-QDs in the HUVEC showed a continuous rising trend within 6 h, weakened after 24 h, and then turned weaker after 48h of the uptake, which is different from the"up-saturation"absorption pattern of PpIX. However, the fluorescence signal was still clear and bright which indicate 3-MPA-QDs were passaged into newborn cells. Migration experiments showed that the target cells carrying 3-MPA-QDs migrated 50 μm grids within 24 h, indicating the cell migration ability was not significantly affected. Co-localization results showed that 3-MPA-QDs localized in lysosomes. Conclusions The 3-MPA-QDs localized in lysosome, and they were easy to be absorbed and hard to be excreted by HUVEC. However, no obvious effects of 3-MPA-QDs were observed on cell proliferation and migration.

A F?rster Resonance Energy Transfer Ratiometric Probe Based on Quantum Dot-Cresyl Violet for Imaging Hydrogen Sulfide in Living Cells / 分析化学

Hydrogen sulfide ( H2S ) has been confirmed as a significant endogenous gaseous signaling molecule involved in various physiological processes.To monitor H2S in living cells, a F?rster resonance energy transfer ( FRET) ratiometric probe based on quantum dot-cresyl violet was developed.In this work, quantum dot nanospheres ( QDS) were firstly synthesiZed via a facile ultrasonication emulsion strategy, and the mixture chloroform solution containing hydrophobic quantum dots and COOH-functionaliZed amphiphilic polymer were successfully transferred into the oil-in-water micelle.The negatively charged quantum dot nanospheres with quantum dots embedded in the polymer matrixes were successfully fabricated after the evaporation of chloroform.And then, these quantum dot nanospheres were condensed with positively charged cresyl violet-aZide ( CV-N3 ) via electrostatic interaction to obtain the QDS-N3 complexes.The as-prepared QDS-N3 complexes were monodispersed nanospheres with an average diameter of about 120 nm.These complexes were taken up by the cell through endocytosis, and they were still stable even in wide pH range.In addition, the QDS-N3 complexes exhibited no cellular toxicity which was verified by MTT assay.In this ratiometric probe, CV-N3 as a FRET acceptor was conjugated to quantum dot nanospheres.The quantum dots emitted at 591 nm and served as the FRET donor;once the aryl aZide on the CV-N3 was reduced to aniline by H2S, the probe emitted at 620 nm.The ratiometric probe allowed the elimination of interference of excitation intensity, intracellular environment and other factors.Furthermore, this method also offered a general protocol for preparing nanosensors for monitoring various small molecular in living cells.

Development of Quantum Dot Submicrobeads-based Fluorescent Immunochromatographic Test Strip for Rapid Detection of Chloramphenicol / 分析化学

A fluorescent immunochromatographic test strip based on the quantum dots submicrobeads (QBs) was developed for quantitative detection of chloramphenicol (CAP). In this method, monoclonal antibody of CAP and OBs complex fluorescent probe was first prepared using 1-ethyl-3-( 3-dimethylaminopropyl ) carbodiimide / N-hydroxysuccinimide coupling approach, then complete antigen CAP-HS-BSA was synthesized and sprayed on nitrocellulose membrane as test line (T line). Similarly, goat anti-mouse antibody was sprayed as control line (C line). The time required for the analysis was 15 min, and the limit of detection (LOD) for CAP was 0. 1 μg / L, with a working range of 0. 1 - 100 μg / L. In spiked milk samples, the test strip demonstrated high recoveries in the range from 93. 3% to 97. 9% with relative standard deviations of less than 7% .

Study on the Percutaneous Properties of Man-PEI25k Nanocomplex under the Treatment of Microneedles / 中国药房

OBJECTIVE:To study the percutaneous properties of Man-PEI25k nanocomplex under the treatment of microneedles. METHODS:Using fluorescent dye water-soluble carboxyl CdSe/ZnS quantum dot (QD) as model drug, Man-PEI25k/QD and Man-PEI25k/QD nanocomplex with different grafting rates(1∶3,1∶6)were formed through electrostatic adherence with PEI25k and Man-PEI25k. The distribution of QD in the active epidermal layer and dermis of skin were observed by confocal microscopy after the treatment of microneedles,using free QD as control. The accumulative retention amounts of QD in the active epidermal layer and dermis of skin were determined by fluorescence spectrophotometer after PEI25k/QD and Man-PEI25k/QD nanocomplex treated with mi-croneedles. RESULTS:The amounts of Man-PEI25k/QD nanocomplex in active epidermal layer and dermis were significantly higher than that of PEI25k/QD nanocomplex under the treatment of microneedles in vivo;the amounts of Man-PEI25k/QD (1∶6) nanocom-plex in active epidermal layer and dermis of skin were significantly higher than that of Man-PEI25k/QD(1∶3)nanocomplex. In in vi-tro transdermal diffusion experiments,microneedles could increase the retention amounts of nanocomplex in active epidermal layer and dermis of skin significantly. The retention amounts of Man-PEI25k/QD nanocomplex in active epidermal layer were increased by 2 times of that of PEI25k/QD under the treatment of microneedles after 48 h;at the same time,in the dermis that was increased by 1.5 times,with statistical significance (P<0.01). CONCLUSIONS:Microneedles can improve the percutaneous properties of Man-PEI25k nanocomplex in active epidermal layer.

Graphene quantum dot modified glassy carbon electrode for the determination of doxorubicin hydrochloride in human plasma$ / 药物分析学报

Low toxic graphene quantum dot (GQD) was synthesized by pyrolyzing citric acid in alkaline solution and characterized by ultraviolet–visible (UV–vis) spectroscopy, X-ray diffraction (XRD), atomic force micro-scopy (AFM), spectrofluorimetery and dynamic light scattering (DLS) techniques. GQD was used for electrode modification and electro-oxidation of doxorubicin (DOX) at low potential. A substantial de-crease in the overvoltage ( ? 0.56 V) of the DOX oxidation reaction (compared to ordinary electrodes) was observed using GQD as coating of glassy carbon electrode (GCE). Differential pulse voltammetry was used to evaluate the analytical performance of DOX in the presence of phosphate buffer solution (pH 4.0) and good limit of detection was obtained by the proposed sensor. Such ability of GQD to promote the DOX electron-transfer reaction suggests great promise for its application as an electrochemical sensor.

Quantum-dot Submicrobead-Based Immunochromatographic Strip for Rapid and Quantitative Detection of Plasmodium Falciparum / 分析化学

A CdTe/ZnSe quantum-dot submicrobead ( QBs ) , which exhibited fluorescence intensity approximately 2800-fold stronger than that of single quantum dots, was conjugated with the anti-histidine rich protein( HRP )-Ⅱ mAbs using N-( 3-( Dimethylamino ) propyl )-N'-ethylcarbodiimide hydrochloride ( EDC ) method as fluorescence probe. The goat anti-HRP-Ⅱ polyclonal antibodies and donkey anti-mouse polyclonal antibodies were sprayed onto the nitrocellulose membrane as test line and control line, respectively. The resultant fluorescence probes were introduced to the immunochromatographic strip for the quantitative determination of Plasmodium falciparum. For determination of Plasmodium falciparum in serum, the QBs based immunochromatographic strips exhibited a good dynamic linear range from 5 . 8 Parasite/μL to 8010 Parasite/μL with a limit of detection of 5. 8 Parasite/μL. The detection time of the proposed QBs based immunochromatographic strips for each sample was only 15 min. Moreover, the recovery rates of the intra-and inter-assay ranged from 93. 0% to 111. 9%, and 98. 3% to 115. 1% respectively, while the relative standard deviations ( RSDs) of intra-and inter-assay were below 5%.