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A new portable molecular imprinting polymer (MIP)-SERS nanoprobe is fabricated by a convenient electrochemical method. Single-layered MoS2 is electrochemically reduced on a screen-printed electrode as the scaffold. Functional monomers o-phenylenediamine (oPD), template theophylline (THP), and SERS-active Au nanoparticles (AuNPs) are then one-step electropolymerized on the scaffold. The morphology of the nanoprobe is found to be a three-dimensional and porous structure. The abundant AuNPs with the size of 45~50 nm are trapped within the growing MIP instead of being confined to the surface. The thickness of MIP film is calculated to 25.1 nm. The nanoprobe displays a strong SERS effect for THP using 532 nm as excitation wavelength with a detection limit (LOD) of 0.01 nM. The SERS peak intensity at 1487 cm−1 increases linearly with the concentration of THP in the range 0.1 nM to 0.1 mM. After the template is removed, the imprint-removed nanoprobe is generated for selective binding of THP. The re-binding kinetics study implies the portable MIP-SERS nanoprobe can reach the adsorption equilibrium within 8 min. This nanoprobe exhibits low SERS interference for structural analogues theobromine (THB) and caffeine (CAF). The nanoprobe was employed to THP determination in tea drink samples, with recoveries ranging from 99.0 to 102.0% and relative standard deviations of

This paper presents a Millimeterwave Monolithic integrated balanced mixer, including its design and analysis method, its circuit and implementation, and the measured performance compared with the predicted one. By designing this MMIC mixer various mathematical methods are used, in which the Method of Conversion Matrix has been extended to meet the requirement of intermodulation analysis. The mixer is realized in a 2/spl times/3 mm/sup 2/ GaAs chip, working in the frequency band of 31-36 GHz with a noise figure less than 10 dB.