Device fabrication and chamber preparation. The Si nanoantennas studied in this paper are fabricated by standard electron beam lithography (EBL) and inductively coupled plasma reactive ion etching (ICP-RIE) on an Si wafer (Virginia Semiconductor Inc.). The resist used is ZEP520 (Zeon Chemicals). After etching, residual resist is removed, resulting in silicon nanoantenna

Optical trapping using plasmonic nanoapertures has proven to be an effective means for the contactless manipulation of nanometer-sized particles under low optical intensities. These particles have included polystyrene and silica nanospheres, proteins, coated quantum dots and magnetic nanoparticles. Here we employ fluorescence microscopy to directly observe the optical trapping process, tracking the position of a polystyrene nanosphere (20 nm diameter) trapped in water by a double nanohole (DNH) aperture in a gold film. We show that position distribution in the plane of the film has an elliptical shape. Comprehensive simulations are performed to gain insight into the trapping process, including of the distributions of the electric field, temperature, fluid velocity, optical force, and potential energy. These simulations are combined with stochastic Brownian diffusion to directly model the dynamics of the trapping process, that is, particle trajectories. We anticipate that the combination of direct particle tracking experiments with Brownian motion simulations will be valuable tool for the better understanding of fundamental mechanisms underlying nanostructurebased trapping. It could thus be helpful in the development of the future novel optical trapping devices.

We report the optical trapping of a single streptavidin-coated CdSe/ZnS quantum dot whose overall diameter is around 15-20 nm, in a microfluidic chamber by an all-dielectric (silicon) nanotweezer with negligible local heating. The use of fluorescence microscopy allows us to readily observe trapping events, tracking the fluorescence emission from, and the position of, each individual trapped quantum dot as a function of time. The blinking behavior of the quantum dots is observed during the trapping process, that is, in the near field region of the silicon nanoantenna. We furthermore show that the continuous wave infrared laser employed to trap the quantum dots can also excite photoluminescence from them via twophoton absorption. We present Maxwell stress tensor simulations of optical forces applied to a single quantum dot in the nanoantenna's vicinity. This work demonstrates that all-dielectric nanotweezers are a promising means to handle quantum dots in solution, enabling them to be localized for observations over extended periods of time.

The pore structures of carbons profoundly affect their properties and functions. The hard template method has been extensively employed to fabricate porous carbons. Generally, the heteroatoms of porous carbons remarkably boost their performances, thus various of strategies have been carried out to incorporate the heteroatoms into porous carbons. The usual hard templates, such as silica nanoparticle and polystyrene sphere, only function as a pore‐forming agent. Herein, nanoscale melamine resin spheres (NMRSs) are fabricated for the first time. NMRSs can be decomposed to generate the template mesopore in situ during the pyrolysis of carbon precursors. Moreover, NMRSs also can work as a nitrogen‐dopant for porous carbons. As a demonstration, the N,P‐codoped hierarchically porous carbons are prepared using NMRSs as both pore‐forming agent and dopant, which exhibit excellent catalytic performances for the oxygen reduction reaction (ORR), close to or better than those of the best performing metal‐free doped carbon catalysts for the ORR. Therefore, this bifunctional template paves a facile pathway to fabricate porous carbons.

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