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We demonstrate a silicon nitride trench waveguide deposited with bowtieantennas for plasmonic enhanced optical trapping. The sub-micron siliconnitride trench waveguides were fabricated with conventional optical lithographyin a low cost manner. The waveguides embrace not only low propagation loss andhigh nonlinearity, but also the inborn merits of combining micro-fluidicchannel and waveguide together. Analyte contained in the trapezoidal trenchchannel can interact with the evanescent field from the waveguide beneath. Theevanescent field can be further enhanced by plasmonic nanostructures. With thehelp of gold nano bowtie antennas, the studied waveguide shows outstandingtrapping capability on 10 nm polystyrene nanoparticles. We show that the bowtieantennas can lead to 60-fold enhancement of electric field in the antenna gap.The optical trapping force on a nanoparticle is boosted by three orders ofmagnitude. A strong tendency shows the nanoparticle is likely to move to thehigh field strength region, exhibiting the trapping capability of the antenna.Gradient force in vertical direction is calculation by using a point-likedipole assumption, and the analytical solution matches the full-wave simulationwell. The investigation indicates that nanostructure patterned silicon nitridetrench waveguide is suitable for optical trapping and nanoparticle sensingapplications.