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Li J.,University of Electronic Science and Technology of China | Li J.,CAS Suzhou Institute of Biomedical Engineering and Technology | Luo H.,University of Electronic Science and Technology of China | Wang L.,University of Electronic Science and Technology of China | And 4 more authors.
Optics Letters | Year: 2015

We report an 1150-nm diode-pump passively Q-switched Ho3-doped ZBLAN fiber laser using topological insulator (TI): Bi2Te3 as the saturable absorber (SA). The TI: Bi2Te3 prepared using the cost-effective hydrothermal intercalation/exfoliation method was dropped onto a CaF2 substrate to fabricate the free-space SA component. It has a low saturable peak intensity of 2.12 MW/cm2 and a high modulation depth of 51.3% measured at 2 μm. Inserting this component into a linear-cavity Ho3-doped ZBLAN fiber laser, stable Q-switched pulses at 2979.9 nm were obtained with the repetition rate of 81.96 kHz and pulse duration of 1.37 μs. The achieved maximum output power and pulse energy were 327.4 mW at a slope efficiency of 11.6% and 3.99 μJ, respectively, only limited by the available pump power. Our work reveals that the TIs are absolutely a class of promising and reliable SAs for pulse generation at 3-μm mid-infrared waveband. © 2015 Optical Society of America.

Zhang L.,CAS Changchun Institute of Applied Chemistry | Zhang L.,Max Planck Institute of Colloids and Interfaces | Belova V.,Max Planck Institute of Colloids and Interfaces | Wang H.,Max Planck Institute of Colloids and Interfaces | And 2 more authors.
Chemistry of Materials | Year: 2014

Here we proposed a model that describes the nucleation of cavitation bubbles on nano/microparticle surfaces, which is of significance for the yet unsolved problem of particle-cavitation interaction. The model was verified through rational experimental design varying parameters including particle size, their shapes and additives. The surface morphology evolution of particles under high intensity ultrasonic irradiation in aqueous solution can be tailored by changing the nucleation energy barrier of cavitation bubbles on particle surfaces. Cavitation-induced breakage of particles under sonication has also been addressed, which predicts the critical effect of the initial size of solid particles in affecting ultrasound-driven intraparticle fracture. These results shed light on the effect of commonly used sonication treatments on nanostructured materials and sonochemical surface modification in particle science and technology. © 2014 American Chemical Society.

Miao P.,CAS Suzhou Institute of Biomedical Engineering and Technology
RSC Advances | Year: 2013

Endotoxin, also referred to as lipopolysaccharide (LPS), is a membrane constituent of gram-negative bacteria, which can initiate immune responses. However, excessive inflammatory responses to endotoxin may lead to life-threatening conditions like irreversible septic shock and even death. Therefore, sensitive detection systems to trace a small amount of endotoxin in foodstuff and medical supplies are urgently needed for health concern. So far, there is an ongoing and extensive research for the development of various endotoxin sensors. Limulus amebocyte lysate (LAL) test is a widespread standard assay. However, LAL test may suffer defects of inadequate stability, high cost and inconvenience. Recently, many advanced techniques are introduced in the fabrication of endotoxin sensors to overcome these defects, such as fluorescence, chemiluminescence, electrophoresis, as well as electrochemical techniques. Among them, electrochemical systems are proved to be effective alternative detection systems with the advantages of low cost, easy operation, rapid analysis, high sensitivity and selectivity. This review summarises recent advances of the electrochemical strategies for the detection of endotoxin, which are designed based on different recognition mechanisms and signal transformations. © 2013 The Royal Society of Chemistry.

Miao P.,CAS Suzhou Institute of Biomedical Engineering and Technology | Miao P.,Nanjing University | Ning L.,Nanjing University | Li X.,Nanjing University
Analytical Chemistry | Year: 2013

Silver ion (Ag+) is a highly toxic heavy metal ion to fungi, viruses, bacteria, and animals. Therefore, Ag+ monitoring in water or food resources has become extraordinarily important within the scope of human health. Here, we report a gold nanoparticles and enzyme cleavage-based dual signal amplification strategy for ultrasensitive detection of Ag+ using electrochemical techniques. This sensing platform for Ag+ has an extremely low detection limit of 470 fM, which also has satisfactory selectivity. Thus, it can be directly used in drinking water and lake water samples. Moreover, the strategy proposed in this work may have potential to be further developed as a generalized platform for the detection of other analytes by designing new DNA sequences for specific recognition. © 2013 American Chemical Society.

Miao P.,CAS Suzhou Institute of Biomedical Engineering and Technology | Miao P.,University of Chinese Academy of Sciences | Wang B.,CAS Suzhou Institute of Biomedical Engineering and Technology | Yu Z.,Arizona State University | And 2 more authors.
Biosensors and Bioelectronics | Year: 2015

MicroRNAs play important roles in gene regulation. They can be used as effective biomarkers for diagnosis and prognosis of diseases like cancers. Due to their intrinsic properties of short length, low abundance and sequence homology among family members, it is difficult to realize sensitive and selective detection with economical use of time and cost. Herein, we report an ultrasensitive electrochemical method for microRNA analysis employing two oligonucleotides and one endonuclease. Generally, a glassy carbon electrode is first covered with gold nanoparticles (AuNPs) mediated by poly(diallyldimethylammonium chloride) (PDDA). Then, thiolated capture probe (CP) with methylene blue (MB) labeled at 5' end is modified on the pretreated electrode. Hybridization occurs among target microRNA, CP and auxiliary probe (AP), forming a star trigon structure on the electrode surface. Subsequently, endonuclease recognizes and cleaves CP on CP/AP duplex, releasing microRNA and AP back to the solution. The two regenerated elements can then form another star trigon with other CP molecules, initiating cycles of CP cleavage and MB departure. Significant decrease of electrochemical signals is thus observed, which can be used to reflect the concentration of microRNA. This proposed method has a linear response to microRNA in a wide range from 100. aM to 1. nM and the sensitivity of attomolar level can be achieved. Moreover, it has high selectivity against single-base mismatch sequences and can be used directly in serum samples. Therefore, this method shows great feasibility for the detection of microRNA and may have potential applications in cancer diagnosis and prognosis. © 2014 Elsevier B.V.

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