Hyaluronidases (HAase) are involved in various physiological and pathological processes and have been reported as urinary marker for bladder cancer. In this study, a novel ratiometric fluorescent sensing system based on both aggregation-induced emission (AIE) and aggregation-induced quenching (ACQ) was developed to quantitatively assess hyaluronidase level. First, a tetraphenylethylene derivative with positive charges (TPE-2N(+), typical AIE molecule) at both ends and an anthracene derivative with positive charge at one end (AN-N(+), typical ACQ molecule) was synthesized. These two positively charged compounds were then mixed with a negatively charged hyaluronan (HA), which induced the aggregation of the compounds as well as the nanoparticles formation as a result of electrostatic complexation, with TPE-2N(+) acting as cross-linking agent. The aggregation also caused the efficient quenching of the emission of AN-N(+) due to ACQ effect, as well as the fluorescence enhancement of TPE-2N(+) due to AIE effect. In the presence of HAase, the enzymatic reaction led to the degradation of HA and triggered disassembly of the nanoparticles; as a result, the emission of AN-N(+) was restored and that of TPE-2N(+) was suppressed. This fluorescence variation affords the system a robust ratiometric biosensor for HAase, and the ratio of fluorescence intensity for AN-N(+) (I414) to that for TPE-2N(+) (I474) can be used as the sensing signal for detecting HAase activity. In this system, hyaluronan serves not only as the scaffold for nanoparticle formation but also as the substrate for enzymatic reaction. This assay system is operable in aqueous media with very low detection limit of 0.0017 U/mL and is capable of detecting HAase in biological fluids such as serum and urine. This strategy may provide a new and effective approach for developing other enzyme assays.

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Through the determination of viscosity average molecular weight, enzyme activity, hydrolysis ratio and reducing sugar concentration, the optimal technological conditions of complex enzymes composed of commercial α-amylase, cellulase and pectinase were investigated. Results indicated that complex enzymes could result in low molecular weight chitosan ranged from 1000 to 4000 after enzymatic degradation for 2 h under the condition of zymolyte ratio 1:5(m/m), pH 5.3 and temperature 56℃, and the structure of those products failed to vary obviously by FTIR analysis.Keywords: Chitosan, Low molecular weight chitosan, Complex enzymes, Preparation Chitosan (chitosan, CTS) is a kind of natural polysaccharide bioactive substances containing nitrogen, tends to be the sixth largest life elements excluding the body necessities viz. sugar, protein, fat, fiber and minerals, and exerts an extensive and intensive application in food, cosmetic and pharmaceutical areas (Zhu, 2006, PP. 41-45; Jiang, 2006, PP. 99-102). Due to its large molecular weight and the structure containing abundant hydrogen bonds, chitosan is only soluble in dilute acid, insoluble in water, and tough to be assimilated by human bodies, which hinders its application dramatically. If chitosan was degraded into LMWC (low molecular weight chitosan) with the molecular weigh less than 10000, its water solubility increased greatly, conducive to human intestinal digestion and absorption, and possessed the functions such as promoting to produce splenic antibody, and lowering cholesterol, blood pressure, blood sugar and blood lipid level in serum and liver (Wei, 2003, PP. 614-617; Kim, 2005, PP. 357-368).Recently, studies on the preparation of water soluble LMWC have attracted many researchers' attention all over the world (Huang, 2002, PP. 381-385). Degradation methods initiated by scholars mainly included chemical, physical and enzymatic degradation. Among them, enzymatic degradation has been recognized as one of the most promising approaches to prepare LMWC, because its reaction condition was moderate without byproducts and the degradation process was easy to monitor. However, the specific enzyme for chitosan was expensive, and its application in industry was limited. The applications of single non-specific enzyme in hydrolyzing chitosan such as α-amylase (Yu, 2008, PP. 464-466; Zhang, 2003, PP. 44-48), pectinase (Ipsita, 2003, PP. 582-588; Cabrera, 2005, PP. 165-172), cellulose (Lin, 2009, PP. 47-53; Xia, 2008, PP. 6751-6762; Han, 2007, PP. 98-101;Xie, 2009, PP. 1895-1899, protease (Li, 2005, PP. 441-448) and so on have been documented, but those enzymes showed limited effects on degradation, even if enhancing their amount. Consequently, we investigated effects of complex enzymes containing cellulase, pectinase and α-amylase on chitosan degradation.

Inkjet printing is a promising technique to fabricate thin-film transistors (TFTs) and integrated complementary metal-oxidesemiconductor (CMOS) circuits because of its patterned Complementary metal-oxide-semiconductor (CMOS) inverters with low power consumption and high noise immunity are essential for realizing practical applications of printed logic gates and circuits. However, the performance of existing printed CMOS inverters is still unsatisfactory because p-type and n-type transistors do not match well. This work demonstrates novel low-voltage and high-performance CMOS inverters using partially printed thin-film transistors (TFTs) on 50 nm HfO 2 /Si substrates based on n-type indium zinc oxides (IZOs) and p-type chirality enriched (9,8) semiconducting single-walled carbon nanotubes (SWCNTs). The high-k dielectric materials grown using atomic layer deposition and (9,8) SWCNTs with relatively large band gaps help to match the characteristics of p-type and n-type transistors-the IZO and SWCNT TFTs exhibit similar mobility on/off ratio, small hysteresis, and low sub-threshold swing at low operating voltages. The hybrid CMOS inverters demonstrate excellent performance with the highest voltage gain up to 45, the largest noise margin of 83% at 1/2 V dd , and the lowest static power consumption of 0.4 µW at V dd of 2 V among recently reported printed CMOS inverters under relatively low annealing temperatures (300 °C). The strategies demonstrated here can be considered as general approaches to realize a new generation of high-performance printed logic gates and circuits. Printable ElectronicsThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.