We design and fabricate a simple micro-system to collect analyte molecules in fluids for surface-enhanced Raman scattering (SERS) detection. The system is based on catalytic Au/SiO/Ti/Ag layered microengines by employing roll-up nanotechnology [1] and the Raman spectrum. Finite-difference time-domain method is employed to illustrate the excitation of localized surface plasmon modes by calculating the electromagnetic field on the rough microengine surface. The bubble-propelled microengines [2] adsorb analyte molecules in fluids, acting as molecule carriers. Pronounced SERS signals are observed on microengines with more carrier molecules compared with the same structure without automatic motions, which indicates outstanding molecule collection performance. Furthermore, optimized collection efficiency of the system is obtained by controlling the fuel concentration. This facile system for molecule collection and detection could spur expanding applications in bioanalysis and lab-on-a-chip research. [3]