Silicon Microcondensor For Exhaled Breath Condensate Collection And On-chip Detection

Exhaled breath condensate(EBC)is a biological fluid derived from droplets in the lower respiratory tract and containing thousands of biological disease markers.The changes of some components of EBC can reflect the pathophysiological state in the lung and airway,which is of great significance for screening respiratory tract pathogen infection,early lung cancer,condition monitoring and curative effect judgment.At the same time,because the collection of EBC mainly depends on cooling human respiratory gas,and its collection method is simple and non-invasive,the detection of EBC components is expected to become a potential non-invasive in vitro diagnostic method.In the current diagnosis process of EBC,the cold wall condensation sampling of exhaled gas is usually carried out by condensing device,and the biomarkers in the samples are subsequently analyzed by means of mass spectrometry and reverse transcription polymerase chain reaction(PCR).However,the existing EBC sampling and testing equipment has some disadvantages,such as large volume,cumbersome operation,easy to cause sample loss in the process of transportation,and can not realize on-site sample collection and real-time detection.To solve the above problems,a new method of EBC acquisition and in situ specific antigen detection based on MEMS technology and chemiluminescence technology is proposed in this paper.The main contents and research results of this paper include:1.A series of microchip structures for EBC condensation and condensate storage were designed by hydrodynamics simulation and wet air Thermodynamics Simulation.The silicon-based microchip was prepared by MEMS process,and the overall flow field,temperature,humidity and condensation effect of these condensation chips with different microstructures were explored.2.A portable EBC condensation acquisition system based on the optimized siliconbased microchip is designed and built.The system includes air pump system and condensation temperature control system,realizes the functions of controllable cooling microchip and driving microchip,and verifies the feasibility of the system and the condensate storage effect of the designed microchip structure.3.The nano structure enhanced enzyme-linked immunosorbent interface improves the specific interface capture ability of the micro condenser for the target biomarkers in EBC.4.Based on the above micro condenser and interface modification scheme,a portable EBC acquisition and chemiluminescence detection device is constructed.Taking pseudovirus-SARS-COV-2 antigen as an example,the specific detection of target biomarkers with different concentrations was carried out systematically,which proved the enhancement effect of nano interface and the feasibility of the system.