Automated chemiluminescent dual-analyte immunoassay based on resolved immunosensing channels

A novel system of series-wound immunosensing channels (SWIC) was proposed for automated chemiluminescent (CL) dual-analyte immunoassay by immobilizing respectively different capture antibodies on the inner walls of series-wound glass channels. This system could use a single enzyme as label to perform multiplex immunoassay in one fluid way. Using α-fetoprotein (AFP) and carcinoembryonic antigen (CEA) as model analytes, the mixture including AFP, horseradish peroxidase (HRP)-labeled anti-AFP antibody, CEA and HRP-labeled anti-CEA antibody was introduced into the SWIC for carrying out the on-line incubation. Upon injection of CL substrate the CL signals from the two immunosensing channels were conveniently resolved and near-simultaneously collected with the aid of optical shutter. AFP and CEA could be rapidly assayed in the ranges of 1.0-100 and 1.0-80 ng/ml with detection limits of 0.41 and 0.39 ng/ml, respectively. The assay results of clinical serum samples were in an acceptable agreement with the reference values. This designed flow-through immunosensing system based on SWIC provided an automated, reusable, simple, sensitive and low-cost approach for multianalyte immunoassay.     

A Uniquely Configured Acetylcholinesterase‐Lecithin Biomimetic Sensing Structure at Cyclohexane/Water Interface for Electrochemical Determination of Fenthion in Organic Solvent

An acetylcholinesterase (AChE)‐lecithin biomimetic structure was constructed at the oil/water interface for the direct determination of fenthion in cyclohexane. Indophenol acetate in oil phase was hydrolyzed by AChE at the two‐phase interface to produce indophenol. Square wave voltammetry was used to monitor the current decrease of substrate to assess AChE activity. The AChE incorporated in the lecithin‐based biomimetic layer possessed higher enzymatic activity and was more sensitive to fenthion inhibition than freestanding AChE. A linear relationship between the inhibition percentage and logarithm of fenthion concentration was obtained in a concentration range from 1 ng/mL to 1 mg/mL.     

Shape‐Selective Alkylation of Naphthalene over Zeolites: Steric Interaction of Reagents with Zeolites

Steric interaction of reagents with zeolites was studied in isopropylation, sec‐butylation, and tert‐butylation of naphthalene (NP) over several large‐pore zeolites to elucidate the mechanism of selective catalysis. Selectivities for dialkylnaphthalene (DAN) isomers were influenced by the type of zeolite and bulkiness of alkylating agent. Selective formation of β,β‐ and 2,6‐diisopropylnaphthalene (DIPN) occurred only over H‐mordenite (MOR) in the isopropylation of NP using propene; bulky transition states of α,α‐ and α,β‐DIPN are excluded because of steric restriction by the channels, resulting in selective formation of β,β‐ and 2,6‐DIPN. However, low selectivities for β,β‐ and 2,6‐DIPN were observed over the zeolites, SSZ‐24 (AFI), SSZ‐55 (ATS), and SSZ‐42 (IFR) with 12‐membered‐ring (12‐MR) pore entrances of one‐dimensional channels, CIT‐5 (CFI), UTD‐1 (DON), and SSZ‐53 (SFH) with 14‐membered‐ring (14‐MR) pore entrances of one‐dimensional channels, and Y‐zeolite (FAU), zeolite β (BEA), and CIT‐1 (CON) with 12‐MR pore entrances of three‐dimensional channels, because their channels are too large for the exclusion of bulky isomers. Catalysis over these zeolites occurs under kinetic and/or thermodynamic control, resulting in predominant formation of α,α‐ and α,β‐DIPN at lower temperatures and an increase of the stable isomer β,β‐DIPN at higher temperatures. The selectivities for β,β‐ and 2,6‐DAN were enhanced with the increase in bulkiness of alkylating agents: 1‐butene for sec‐butylation and 2‐methylpropene for tert‐butylation. In particular, β,β‐di‐tert‐butylnaphthalene (DTBN) was selectively formed in the tert‐butylation. The selectivities for β,β‐ and 2,6‐DAN were enhanced even in large channels: the transition states of the least bulky isomers only fit the channels because other bulky isomers are excluded by steric restriction of the channels. However, tert‐butylation over FAU, BEA, and CON had selectivities for 2,6‐DTBN of around 50–60%, although selectivities for β,β‐DTBN were almost 100% selectivity; these zeolites can hardly recognize the differences between 2,6‐ and 2,7‐DTBN. The results indicate that the fitting of the least bulky isomers to zeolite channels, leading to the exclusion of other bulky isomers, is essential for highly shape‐selective catalysis.     

基于蓝黄磷光二元互补色的高效聚合物白光器件

研究了基于互补色的高效聚合物白光器件,双色材料包括蓝绿光材料双(4,6-二氟苯基吡啶-N,C2)吡啶甲酰合铱(Firpic)和黄光材料三[3-(2,6-二甲基苯氧基)-6-(2-噻吩基)-哒嗪]铱(Fs-1),器件结构为ITO/PEDOT(40 nm)/PVK:OXD-7:Firpic:Fs-1(80 nm)/Ba(4 nm)/Al(120 nm).当发光层材料PVK∶OXD-7∶Firpic∶Fs-1质量比为63∶27∶10∶0.25时,用溶液加工方法得到高效白光器件,此时CIE色坐标为(0.30,0.39),最大电流效率为10.8 cd.A-1,亮度可达到4200 cd.m-2.在此基础上,引入水溶性电子注入材料聚[9,9-二(3′-N,N-二甲基胺基丙基-2,7-芴-2,7-交-(9,9-二辛基芴)](PFN)修饰阴极界面,使载流子注入和传输更平衡,当阴极为PFN(20 nm)/Al(120 nm)时,电流效率获得显著改善,达到13.1 cd.A-1,此时电流密度为4.9 mA.cm-2,亮度可达到6096 cd.m-2,白光器件的色坐标为(0.33,0.39),同时发光光谱稳定.另外通过电致发光(EL)、光致发光(PL)光谱及能级结构图分析了载流子俘获和能量转移在发光中的作用.     

Z-scan measurement for the nonlinear absorption and the nonlinear refraction of poly1,4-diazophenylene-bridged-tris(8-hydroxy-quinoline) aluminum (PDPAlq3)

The nonlinear optical properties of the poly1,4-diazophenylene-bridged-tris(8-hydroxy-quinoline) aluminum (PDPAlq₃) solution were studied using single beam Z-scan technique with a continuous-wave Diode laser radiation at 657.2 nm with 10 Hz repetition rate. The results show that the solution of PDPAlq₃ exhibits large nonlinear refractive index (n₂ = −1.7642 × 10⁻¹² m²/W) and nonlinear absorption coefficient (β = 1.12 × 10⁻⁶ m/W). The negative sign of the nonlinear refractive index n₂ indicates that the material exhibits self-defocusing optical nonlinearity. The evaluation of the figure of merit (W = 1.8) shows that the solution of PDPAlq₃ is sufficient for application in all-optical switching technology. These results show that the solution of PDPAlq₃ have potential application in nonlinear optics.     

The analysis of the error statistics in a 5 × 40 Gbit/s fibre link with hybrid amplification

We quantify the error statistics and patterning effects in a 5 × 40 Gbit/s WDM RZ-OOK SMF/DCF fibre link using hybrid Raman/EDFA amplification. By extensive use of a numerical model, we determine how the error statistics change with the transmission distance. This knowledge is used as a basis for a constrained coding technique in order to improve the transmission error rate. We propose an adaptive constrained code for mitigation of the patterning effects and demonstrate that this approach can substantially reduce the bit error rate (BER) even for very large values of the channel BER (BER > 10^− 1). The proposed technique can be used in combination with forward error correction schemes (FEC) to extend the range of channel BERs that an FEC scheme is effective over.