Plasmonic sensing has a great potential in the portable detection of human tumor markers, among which the carcinoembryonic antigen (CEA) is one of the most widely used in clinical medicine. Traditional plasmonic and non-plasmonic methods for CEA biosensing are still not suitable for the fast developing era of Internet of things. In this study, we build up a cost-effective plasmonic immunochip platform for rapid portable detection of CEA by combining soft nanoimprint lithography, microfluidics, antibody functionalization, and mobile fiber spectrometry. The plasmonic gold nanocave array enables stable surface functionality, high sensitivity, and simple reflective measuring configuration in the visible range. The rapid quantitative CEA sensing is implemented by a label-free scheme, and the detection capability for the concentration of less than 5 ng/ml is achieved in clinical experiments, which is much lower than the CEA cancer diagnosis threshold of 20 ng/ml and absolutely sufficient for medical applications. Clinical tests of the chip on detecting human serums demonstrate good agreement with conventional medical examinations and great advantages on simultaneous multichannel detections for high-throughput and multi-marker biosensing. Our platform provides promising opportunities on low-cost and compact medical devices and systems with rapid and sensitive tumor detection for point-of-care diagnosis and mobile healthcare.

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In order to identify engine status correctly, a novel method of abnormal noise diagnosis of internal combustion engine based on the wavelet spatial correlation filter (WSCF) and symmetrized dot pattern (SDP) is proposed. Firstly, the gathered acoustic signals are processed by wavelet spatial correlation filter in order to improve the SNR (signal-to-noise ratio); then, the filtered signals are transformed into spatial polar coordinates through SDP method. The experimental results demonstrate that the proposed methods are good classifiers and it can diagnose abnormal sound of engine accurately.

The study investigates behaviors of charge accumulation on an insulated surface from micro perspective via the numerical method. A coupling bridge between the micro-ion reaction system and the macroscopic multi-physical field was constructed by means of the electronic energy distribution function, which revealed the coupling mechanism in the process of corona charge. Moreover, it revealed the transport and accumulation mechanism of charge on the surface of insulating materials. 2D axisymmetric finite element model was built based on the multi-physical field coupling theory. 10 kV negative voltage was applied using a pin-plate electrode structure and polyimide film was taken as insulated surface to simulate the dynamic charge accumulation behaviors in the corona discharge process. The generation, migration and distribution laws of charged ions and electrons in different stages of corona discharge process were given. Charge distribution laws in different stages of charge process of polyimide were given and discussed. When corona discharge reached quasi-stationary state, the total charge number accumulated on the surface was at 10-10 Coulomb order of magnitude, and the drift current was at 10-7 ampere order of magnitude. An experimental platform was set up to test drift current and charge distribution under quasi-stable discharge state. The results show that the simulation results and the experimental data under quasi-stable state are consistent, thus indirectly verifying the correctness of the proposed numerical simulation algorithm and its simulation results.