Low-abundance biomolecule detection is very crucial in many biological and medical applications. In this paper, we present a novel electrolyte-gated graphene field-effect transistor (EGFET) biosensor consisting of acoustic tweezers to increase the sensitivity. The acoustic tweezers are based on a high-frequency bulk acoustic resonator with thousands of MHz, which has excellent ability to concentrate nanoparticles. The operating principle of the acoustic tweezers to concentrate biomolecules is analyzed and verified by experiments. After the actuation of acoustic tweezers for 10 min, the IgG molecules are accumulated onto the graphene. The sensitivities of the EGFET biosensor with accumulation and without accumulation are compared. As a result, the sensitivity of the graphene-based biosensor is remarkably increased using SMR as the biomolecule concentrator. Since the device has advantages such as miniaturized size, low reagent consumption, high sensitivity, and rapid detection, we expect it to be readily applied to many biological and medical applications.

Steam dryness detection is crucial in the field of oil exploitation. Steam dryness too high will be dangerous, whereas steam dryness too low will affect the efficiency of extraction. Therefore, real-time, high-precision detection of steam dryness is essential. The methods for detecting steam dryness include chemical, thermodynamic, radiometric, and microwave. The manual test method possesses the best detection accuracy. However, the real-time performance is not good, and the detection process is cumbersome. Here we propose using a silver nitrate solution to titrate chloride ions and combining them with the change in the absorbance of the solution to determine the endpoint of the titration. We report that the automatic chloride ion concentration measurement was a rep and that the detection of chloride ion concentration was 15 mg/L. The detection linearity reached 0.992. Therefore, our titration endpoint judgment method has better anti-interference.