Devices for detection of analytes in samples of various complexities are provided. The devices allow reflux of liquid into a sample-receiving member, providing for suitable analyte dilution and preventing leakage of cells or particulate material into the signal generation member. In one aspect, the devices are used to test analytes in biological samples such as blood, serum, plasma or other body fluids. In another aspect, the devices are used to test samples from tissues, such as organ tissues, tumor samples, or other body parts. In a further aspect, the devices are used to test microbial samples, food samples, or any other sample from which the analyte of interest can be captured into the reflux device.