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Binary naoparticles composed of a superparamagnetic Fe(3)O(4) core and an Au nanoshell were prepared via a high-temperature hydrolysis reaction followed by seed-mediated growth. The nanoprobes render simultaneous dual functions of both fast magnetic response and local surface plasmon resonance. Using these nanoprobes, analyte molecules can be easily biologically captured, magnetically concentrated, and analyzed by surface-enhanced Raman scattering (SERS). Particularly, the complex particles were assembled under magnetic force direction into a SERS substrate. It was found to possess both a high enhancement factor (10(6)) and high homogeneity of "hot spot" distribution (fluctuation less than 20% for a 1 μm(2) area) with 4-aminothiophenol as the analyte.

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This article is concerned with event-triggered bipartite tracking consensus under an asynchronous sampling setting, where the event-triggering condition for each agent is allowed to be intermittently examined at its own sampling instants. First, a novel distributed protocol based on independent sampling period is presented, with which the bipartite tracking consensus issue can be transformed into the convergence problem of the augmented error system. Then, with the help of tools from graph theory and matrix analysis, a sufficient condition on the bipartite tracking consensus is derived. By appropriately choosing control parameters, it is shown that the bipartite tracking consensus can be achieved under the proposed protocol for the graph that contains a directed tree and the subgraph among followers is structurally balanced. Finally, numerical simulations are provided to verify the theoretical results.

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This paper is concerned with a leader-following consensus problem of second-order multiagent systems with a constant acceleration leader and time-varying delays. At first, a distributed control protocol for every agent to track the leader is proposed; then by utilizing the Lyapunov-Razumikhin function, the convergence analysis under both fixed and switching interconnection topologies is investigated. For the case of fixed topology, a sufficient and necessary condition is obtained, and for the case of switching topology, a sufficient condition is derived under some assumptions. Finally, simulation examples are provided to demonstrate the effectiveness of the theoretical results.