Southwest University

About: Southwest University is a education organization based out in Chongqing, China. It is known for research contribution in the topics: Population & Bombyx mori. The organization has 29772 authors who have published 27755 publications receiving 409441 citations. The organization is also known as: Southwest University in Chongqing & SWU.

Event-Triggered Distributed Average Consensus Over Directed Digital Networks With Limited Communication Bandwidth

Abstract: In this paper, we consider the event-triggered distributed average-consensus of discrete-time first-order multiagent systems with limited communication data rate and general directed network topology. In the framework of digital communication network, each agent has a real-valued state but can only exchange finite-bit binary symbolic data sequence with its neighborhood agents at each time step due to the digital communication channels with energy constraints. Novel event-triggered dynamic encoder and decoder for each agent are designed, based on which a distributed control algorithm is proposed. A scheme that selects the number of channel quantization level (number of bits) at each time step is developed, under which all the quantizers in the network are never saturated. The convergence rate of consensus is explicitly characterized, which is related to the scale of network, the maximum degree of nodes, the network structure, the scaling function, the quantization interval, the initial states of agents, the control gain and the event gain. It is also found that under the designed event-triggered protocol, by selecting suitable parameters, for any directed digital network containing a spanning tree, the distributed average consensus can be always achieved with an exponential convergence rate based on merely one bit information exchange between each pair of adjacent agents at each time step. Two simulation examples are provided to illustrate the feasibility of presented protocol and the correctness of the theoretical results.

A novel electrochemical biosensor based on hemin functionalized graphene oxide sheets for simultaneous determination of ascorbic acid, dopamine and uric acid

Abstract: Graphene oxide (GO) has been demonstrated to be functionalized by hemin without any other reducing agents and the hemin functionalized graphene oxide (H-GO) hybrid nanomaterial was obtained under the condition of sonication, which could be ascribed to the π–π stacking and cation-π interactions between GO and hemin molecules. H-GO composite, characterized by scanning electron microscopy and UV–vis absorption spectroscopy, was used for preparation of the modified electrode considering its great electrocatalytic activity, large surface area, and abundant active sites. Due to the unique structure and excellent properties, H-GO modified glassy carbon electrode (GCE) showed high electrocatalytic activities for the oxidation of ascorbic acid, dopamine, and uric acid, achieving the simultaneous determination for those three different kinds of biomolecules with detection limits of 0.3, 0.17, and 0.17 μmol L−1 (S/N = 3), respectively. In addition, the proposed biosensor exhibited high selectivity and good stability, which could be applied for the electrochemical determination in practical samples with satisfying results.

Electrochemiluminescence Resonance Energy Transfer System: Mechanism and Application in Ratiometric Aptasensor for Lead Ion

Abstract: In this paper, a novel electrochemiluminescence resonance energy transfer (ECL-RET) system from O2/S2O82– to a kind of amino-terminated perylene derivative (PTC-NH2) was demonstrated for the first time, which was then applied to construct a ratiometric aptasensor for lead ion (Pb2+) detection. First, gold-nanoparticles-functionalized fullerene nanocomposites (AuNPs@nano-C60) were coated on a glassy carbon electrode (GCE), and then thiol-modified assistant probes (APs) were attached on AuNPs@nano-C60/GCE. Then the resultant electrode was hybridized with capture probes (the aptamer of the Pb2+, abbreviated as CPs) to generate DNA duplexes, which could induce PTC-NH2 to be intercalated into the dsDNA grooves by the electrostatic adsorption. Herein, ECL dual peaks at −0.7 V (vs Ag/AgCl) and −2.0 V (vs Ag/AgCl) were obtained when the prepared aptasensor was detected in air-saturated S2O82– solution, which could be attributed to the emission of excited dimmers (π-excimers) (1(NH2–PTC)2*) and 1(O2)2*, respective...