Improved A* Algorithm for Path Planning of Spherical Robot Considering Energy Consumption.

Spherical robots have fully wrapped shells, which enables them to walk well on complex terrains, such as swamps, grasslands and deserts. At present, path planning algorithms for spherical robots mainly focus on finding the shortest path between the initial position and the target position. In this paper, an improved A* algorithm considering energy consumption is proposed for the path planning of spherical robots. The optimization objective of this algorithm is to minimize both the energy consumption and path length of a spherical robot. A heuristic function constructed with the energy consumption estimation model (ECEM) and the distance estimation model (DEM) is used to determine the path cost of the A* algorithm. ECEM and DCM are established based on the force analysis of the spherical robot and the improved Euclidean distance of the grid map, respectively. The effectiveness of the proposed algorithm is verified by simulation analysis based on a 3D grid map and a spherical robot moving with uniform velocity. The results show that compared with traditional path planning algorithms, the proposed algorithm can minimize the energy consumption and path length of the spherical robot as much as possible.

Polyoxometalate@magnetic graphene as versatile immobilization matrix of Ru(bpy)3(2+) for sensitive magneto-controlled electrochemiluminescence sensor and its application in biosensing.

We demonstrated here the exploration of polyoxometalate (POM) coated magnetic Fe3O4/reduced graphene oxide (POM@mrGO) composite as the versatile immobilization matrix for the electrochemiluminescence (ECL) agent Ru(bpy)3(2+). The effective modification of Ru(bpy)3(2+)/POM@mrGO hybrid simply involved using magnetic electrode showed 10-fold ECL intensity increase than that observed for Ru(bpy)3(2+)/Nafion@mrGO to the same concentration of nicotinamide adenine dinucleotide (NADH), which is largely due to POM׳s good electrocatalytic activity towards NADH oxidation. These findings allowed the stable and ultrasensitive ECL detection of NADH as low as 0.1 nM. The good stability and high sensitivity of the magneto-controlled ECL sensor enabled us to explore the feasibility of applying the sensing platform to fabricating the ECL biosensors in which the NADH was produced from the dehydrogenase-based enzymatic reaction in the presence of NAD(+) cofactor. With L-lactate dehydrogenase as a model, a L-lactate biosensor was successfully constructed where we showed that the ECL intensity of the biosensor increased with the increasing L-lactate concentration. Excellent performance of the presented biosensor has been achieved including a wide linear range extended from 5.0×10(-9) M to 5.0×10(-4) M and an extremely low detection limit of 0.4 nM. Such sensing strategy combines enzymatic selectivity with simple sensor preparation can be used as a new and biocompatible platform for dehydrogenase-based ECL biosensing.

Ultrasensitive photoelectrochemical sensing of nicotinamide adenine dinucleotide based on graphene-TiO2 nanohybrids under visible irradiation.

In this paper, the photoelectrochemical behavior of graphene-TiO(2) (G-TiO(2)) nanohybrids was investigated in the visible region and a new photoelectrochemical sensor for sensitive determination of nicotinamide adenine dinucleotide (NADH) was proposed. Under visible light, the G-TiO(2) nanohybrids possessed enhanced photocurrent, which was nearly 5 times than that of pure TiO(2) nanocrystals (NCs). Based on the enhanced photocurrent of G-TiO(2) nanohybrids toward NADH, a new photoelectrochemical methodology for ultrasensitive determination of NADH was developed. The proposed sensor showed linearly enhanced photocurrent by increasing the NADH concentration from 1.0×10(-8) to 2.0×10(-3) M with a low detection limit of 3.0×10(-9) M. Furthermore, this sensor exhibited good selectivity and stability towards NADH determination. This strategy opens up a new avenue for the application of graphene-based hybrids in the field of photoelectrochemical sensing and monitoring.