Min Guan

In this letter, we focus on the relationship between modification bioparticle density (N) and biological regulation ability in extended gate HEMT (EG-HEMT) biosensors. By analyzing, we demonstrate that under the same gate electrodes size (S _g) and concentration, N is exponentially related to the area of sensing regions (y) and has fixed exponential magnification −0.65 ± 0.05. This formula had been demonstrated to have perfect universality when testing protein and small molecules. Finally, we apply N to the structural design of EG-HEMT biosensors and projected that 10 y structure has both high biological regulation ability of biosensors and efficient utility of chips.

Herein, we designed several structures of GaAs/AlGaAs extended gate high electron mobility transistors (EG-HEMT) for cTnI detection, in order to explore the mechanism of bio-detection, the limit of detection (LOD) as well as the application in clinical detection. The experiment carried out that 50y structure of EG-HEMT biosensor, whose extended electrode is 50 times as large as the gate, has highest biological regulation ability ( δ). Meanwhile, the concentration range of cTnI detection using 50y EG-HEMT biosensor is about 100 fg ml ^-1 to 10 μg ml ^-1 , which is much broader than that of Unicel Dxl800 (usually be used in clinical detection). Furthermore, due to the influence of parasitic resistance and other factors, δ increases with the increase of y, but the rising rate of δ decreases at the same time. By comparing the detecting results of clinical samples, 30y EG-HEMT is the best in the detection of cTnI concentration with a relative error of 6%. In a higher concentration range, it is more accurate than that of the Unicel Dxl800, breaking through its limit.

A bowtie triangular ring (BTR) metamaterial sensor with strongly enhanced electric- field is designed. The Q factor and sensitivity could be improved through introducing the splits on the BTR , which benefits for the high-accuracy sensing.

The high electron mobility transistor (HEMT)-based biosensors are highly competitive in the ultimate application of portable and point-of-care testing. Herein, we have demonstrated highly sensitive and real-time detection of cardiac troponin I (cTnI), a biomarker for the diagnosis of acute myocardial infarction (AMI) using AlGaAs/GaAs HEMT-based biosensors. The device has achieved a lower detection limit of 1 pg/ml in the buffer solution and less than 30 s response time, which demonstrated significant promise in the early diagnosis and screening of AMI. In addition, our results are consistent with the enzyme-linked immunosorbent assay according to the AMI patient’s blood test results. Furthermore, by comparing the two HEMT structures, we also calculated the equilibrium dissociation constant (K_D) of the cTnI and cTnI antibody and analyzed the sensing mechanism. The results show that this method is very promising for early diagnosis of AMI.

The variable temperature transient electroluminescence characteristics in BCP-based organic light emitting diodes (OLEDs) are studied in this paper. The temperature difference compensation effect (TDCE) is found in the BCP-based OLEDs with different structures by transient electroluminescence response. The TDCE was affected by electron mobility and electron suppression traps, when the temperature is between 200 K and 300 K, the compensation temperature difference caused by electron mobility and electron suppression traps is 25 K and 20 K, respectively. Moreover, we calculate the derivative of the effective exciton numbers to temperature, and find that the inflection point temperature difference between different devices is consistent with the compensation temperature difference.

Space charge capacitance and the physical mechanism of negative capacitance in organic light-emitting diodes (OLEDs) by transient current response analysis are investigated for the first time.

Nano-textured 4H–SiC homoepitaxial layers (NSiCLs) were grown on 4H–SiC(0001) substrates using a low pressure chemical vapor deposition technique (LPCVD), and subsequently were subjected to high temperature treatments (HTTs) for investigation of their surface morphology evolution and graphene growth. It was found that continuously distributed nano-scale patterns formed on NSiCLs which were about submicrons in-plane and about 100 nanometers out-of-plane in size. After HTTs under vacuum, pattern sizes reduced, and the sizes of the remains were inversely proportional to the treatment time. Referring to Raman spectra, the establishment of multi-layer graphene (MLG) on NSiCL surfaces was observed. MLG with sp² disorders was obtained from NSiCLs after a high temperature treatment under vacuum at 1700 K for two hours, while MLG without sp² disorders was obtained under Ar atmosphere at 1900 K.

Cesium azide (CsN₃) doped 2,9‐bis(naphthalen‐2‐yl)‐4,7‐diphenyl‐1,10‐phenanthroline (NBphen) has been demonstrated as an efficient electron‐injection layer (EIL) in this work. Advantageous for its low evaporation temperature and air stability, CsN₃ is employed as an n‐dopant to replace the reactive alkali metals or alkali metal compounds. Organic light‐emitting diodes utilizing this composite EIL exhibit highly improved current density–luminance–voltage characteristics compared to the control device with LiF. When C545T‐doped Alq₃ is used as an emitting layer, a maximum current efficiency of 10.4 cd A⁻¹ can be reached. Our results indicate that this CsN₃‐doped NBphen composite layer has great potential as an alternative EIL in organic electronic devices.