Increased serum LOXL2 concentration in pelvic inflammatory disease with pelvic adhesion.

BACKGROUND: Lysyl oxidase-like 2 (LOXL2) belongs to a family of the LOX secretory enzyme, which involves the cross-linkage of extracellular matrix (ECM) proteins. Here, we aimed to analyze the correlation between serum LOXL2 and pelvic adhesion in chronic pelvic inflammatory disease (PID). METHODS: A total of 143 patients with PID and 130 healthy controls were included in this study. The serum levels of LOXL2 were measured using enzyme-linked immunosorbent assay (ELISA) kits. The patients were divided into non-adhesion group (102 cases) and adhesion group (41 cases). RESULTS: It was found that the serum level of LOXL2 expression was elevated in PID patients compared with healthy controls, and was elevated in PID patients with pelvic adhesion compared to patients without adhesion. In all PID patients, serum LOXL2 level was positively correlated with matrix metalloproteinases-9 (MMP-9), transforming growth factor-ß (TGF-ß1), whole blood viscosity (WBV) at low shear rate (LSR), WBV at high shear rate (HSR), and hematocrit (HcT). Multivariate logistic regression analysis showed that serum LOXL2 level was an independent risk factor for pelvic adhesion in PID patients (OR = 1.058; 95% CI = 1.030-1.086, P < 0.001). CONCLUSIONS: Serum LOXL2 level not only predicts the presence of PID, but serum LOXL2 concentration is also associated with the presence of pelvic adhesions.

Selective Sensing of Copper Ions by Mesoporous Porphyrinic Metal-Organic Framework Nanoovals.

Copper is a common element in the environment and human body. Exposure to high concentrations of Cu2+ potentially causes health issues, such as Wilson and Alzheimer's diseases. It is of great importance for the highly selective and sensitive detection of Cu2+. In this work, a porous metal-organic framework (MOF), PCN222, is employed for the selective and sensitive determination of Cu2+. The selectivity of PCN222 relies on the interaction between Cu2+ and the porphyrin core of PCN222. PCN222 stacked with porphyrin rings exhibits solvent adaptability, which overcomes the drawback of the natural porphyrinic enzyme (such as HRP). PCN222 is used for constructing a sensor which shows a linear range of Cu2+ concentration from 0.4 to 13 µmol L-1, and its limit of detection (LOD) is 50 nmol L-1. The response time is less than 3 s, which is faster than previous methods. This work opens up a new route to MOF applications in the detection of metal ions in complex environments.

Analysis of internal spermatic vein embolization through catheter versus laparoscopic high ligation in treatment of left varicocele.

OBJECTIVE: Varicocele is a common disease in young and middle-aged men. This study aims to compare the efficacy of internal spermatic vein embolization of left varicocele versus laparoscopic high ligation. METHODS: From January 2017 to September 2018, a total of 69 varicocele patients were admitted and given the opportunity to choose the treatment option. Among these, 26 patients were treated with sclerosing agent injection, while 43 patients underwent laparoscopic surgery. They were followed up for 12 months after surgery, and the technical success rate, recurrence rate, complication rate, cost, operative time, and hospitalization time with regard to these two methods were analyzed. RESULTS: All patients completed the medical procedures. There was no recurrence in patients in the sclerotherapy group during the follow-up period; however, the complication rate was 19.2%. Furthermore, the operative time, hospitalization time, and cost of treatment were 31.1 ± 11.1 min, 1.2 ± 0.49 days, and 9613.11 ± 895.97 Yuan, respectively. In the laparoscopic group, 9 patients underwent laparoscopic bilateral high ligation, while 34 patients received treatment on the left side alone. The recurrence rate of left varicocele was 4.7% and the complication rate was 44.2%. Furthermore, the operative time, hospitalization time, and treatment cost were 50.4 ± 14.48 min, 4.0 ± 2.02 days, and 10,948.29 ± 2547.00 Yuan, respectively. Moreover, there were statistically significant differences (P < 0.05) in operative time, hospitalization time, and treatment cost. Patients in the sclerotherapy group had an advantage with respect to the overall complication rate when compared with patients from the laparoscopic group (X2 = 4.448, P < 0.05), and there was a statistically significant difference in hydrocele (X2 = 4.555, P < 0.05). However, there was no significant difference in the recurrence rate between these two groups (X2 = 1.245, P > 0.05). CONCLUSION: Patients who underwent sclerotherapy showed a higher technical success rate, a lower recurrence rate, fewer complications, and shorter hospitalization time compared to those treated with laparoscopic ligation. Transcatheter sclerosing agent injection may be a preferable treatment option for patients with unilateral varicocele.

Comparison of the Analgesic and Anti-Inflammatory Effects of Xiaoyuningkun Decoction with Cynanchum Paniculatum and Fukeqianjin in a Mouse Model of Pelvic Inflammatory Disease.

BACKGROUND Preclinical and clinical studies have shown that the extract of Cynanchum paniculatum (bunge) kitag and the fukeqianjin formulation have beneficial effects in pelvic inflammatory disease (PID). This study aimed to compare the effects of Cynanchum paniculatum and fukeqianjin with a new decoction, xiaoyuningkun, consisting of Melia toosendan, Angelica biserrata, and Cynanchum paniculatum, in a mouse model of PID. MATERIAL AND METHODS The mouse model of PID included injection of the upper genital tract with hydrochloric acid (HCl) and lipopolysaccharide (LPS). The control group underwent sham treatment with 0.9% physiological saline. Cynanchum paniculatum, fukeqianjin, and xiaoyuningkun decoction were administered orally for 15 days. Acetic acid-induced writhing and thermal nociception hot plate tests evaluated the analgesic effects of treatment. Mouse uterus and Fallopian tubes were examined histologically to evaluate the degree of inflammation. Immunohistochemistry was used to measure the protein expression of intercellular adhesion molecule-1 (ICAM-1) and vascular endothelial growth factor (VEGF). Enzyme-linked immunosorbent assay (ELISA) measured serum levels of inflammatory cytokines. RESULTS Treatment with xiaoyuningkun decoction significantly reduced the pain threshold in the mouse model of PID and the degree of inflammation in the uterus and Fallopian tubes compared with Cynanchum paniculatum and fukeqianjin. Cynanchum paniculatum decoction significantly reduced the serum levels of interleukin-1ß (IL-1ß), tumor necrosis factor-alpha (TNF-alpha), ICAM-1, and VEGF, and the expression of ICAM-1 and VEGF in the mouse uterus and Fallopian tubes. CONCLUSIONS The new xiaoyuningkun decoction had analgesic and anti-inflammatory effects in the mouse model of PID, possibly by inhibiting ICAM-1, VEGF, and inflammatory cytokines.

C-Aryl glucoside SGLT2 inhibitors containing a biphenyl motif as potential anti-diabetic agents.

A series of highly active C-aryl glucoside SGLT2 inhibitors containing a biphenyl motif were designed and synthesized for biological evaluation. Among the compounds tested, compound 16l demonstrated high inhibitory activity against SGLT2 (IC50=1.9 nM) with an excellent pharmacokinetic profile. Further study indicated that the in vivo efficacy of compound 16l was comparable to that of dapagliflozin, suggesting that further development would be worthwhile.

[Chinese consensus of cardiopulmonary resuscitation guides prevention, treatment and rescue of cardiac arrest in pregnancy].

Pregnant women are a group of people in a special period, once sudden cardiac arrest (CA) occurs, it will threaten the life of both mother and child. It has become a great challenge for hospital, doctors and nurses to minimize maternal mortality during pregnancy. All the efforts should ensure the safety of both mother and child throughout the perinatal period. Because difference of the cardiopulmonary resuscitation strategies for common CA patients of the same age, the resuscitation strategies for CA patients during pregnancy need consider the patient's gestational age and fetal condition. Different resuscitation techniques, such as manual left uterine displacement (MLUD), will involve perimortem cesarean delivery (PMCD). At the same time, drugs should be reasonably used for different causes of CA during pregnancy, such as hypoxemia, hypovolemia, hyperkalemia or hypokalemia and other electrolyte disorders and hypothermia in 4Hs, as well as thrombosis, pericardial tamponade, tension pneumothorax and toxicosis in 4Ts. In view of the fact that many causes of CA in pregnancy are preventable, it is more necessary to introduce guidelines for CA in pregnancy in line with our national conditions for clinical guidance. This paper systematically reviewed the pathophysiological characteristics of CA during pregnancy, the high-risk factors of CA during pregnancy, and identified the correct resuscitation methods and prevention and treatment strategies of CA during pregnancy.

Random amphiphilic copolymeric sub-micro particles as a carrier shielding from enzymatic attack for peptides and proteins delivery.

The development of peptide drugs and therapeutic proteins is limited by their rapid clearance in liver and other body tissues by proteolytic enzymes, and consequently peptides and proteins are difficult to administer except by injection. There is a growing effort to circumvent these problems by designing strategies to deliver these drugs to specific site of the body. Among them, this peptide carrier presents several advantages for protein therapy including stability in physiological buffer and lack of toxicity. Here, we have been developing a novel bioadhesive polymer matrix that protects entrapped proteins and peptides from degradation by serine protease. Poly(2-lactobionamidoethyl methacrylate-ran-3-acrylamidophenylboronic acid-ran-methoxypolyethylene glycol methacrylate) glycopolymers were synthesized and could self-assemble into the sub-micro particles. The loading capability of insulin, as a drug model, and the insulin release from the particles were assessed. The inhibitory effect of the particles toward trypsin, elastase, and chymotrypsin was evaluated in vitro. Insulin was effectively encapsulated, up to 10%, and could be stained release in vitro. These glycopolymers displayed a strong inhibitory effect toward these exopeptidases. Therefore, novel glycopolymers with excellent inhibitory activity against proteolytic enzymes and reasonable mucoadhesivity might be a useful tool in overcoming the enzymatic barrier to the mucosal delivery (e.g. nasal and buccal) of therapeutic peptides or proteins.

Pharmacokinetics and safety of a new bioengineered thrombolytic agent, human tissue urokinase type plasminogen activator in Chinese healthy volunteers.

The aim of our study was to investigate the pharmacokinetics and safety of human tissue urokinase type plasminogen activator (HTUPA) in healthy Chinese subjects after intravenous administration. Thirty-two subjects were given intravenous injection doses of 5-35 mg of HTUPA for safety evaluation. Twenty-four subjects were given 10, 20 or 30 mg HTUPA for pharmacokinetic assessment. Safety and tolerance were evaluated by monitoring adverse events, laboratory parameters, electrocardiography and vital signs. HTUPA concentration in human serum samples was determined by an enzyme-linked immunosorbent assay (ELISA) method. The main pharmacokinetic parameters were calculated by DAS software. HTUPA was generally well tolerated and in the whole study course no serious adverse events occurred. The main pharmacokinetic parameters were as follows: geometric mean [95% confidence interval, CI] for t1/2 were 1.5 (1.4, 1.6), 1.3 (1.2, 1.4), and 1.2 (1.2, 1.3) h, AUC0-t were 1.0 (0.7, 1.3), 2.1 (1.5, 2.7), and 5.6 (4.7, 6.6) mg h L(-1), AUC0-∞ were 1.1 (0.8, 1.3), 2.1 (1.5, 2.7), and 5.8 (4.7, 6.7) mg h L(-1) for 10, 20, and 30 mg group, respectively. The main pharmacokinetic parameters were not significantly different between males and females (P>0.05). No serious adverse events were reported by the subjects or revealed by clinical or laboratory examinations, suggesting the given doses were safe and well tolerated.

[Analysis of the occurrence of pulmonary embolism in 20 years in single medical center].

OBJECTIVE: To evaluate the correlation of pulmonary embolism (PE) and original diseases by retrospectively analysis of the patients for 20 years in single medical center. METHODS: Five hundred and five patients with PE were admitted and treated in General Hospital of Chinese PLA from January 1989 to January 2009, and their clinical data were retrospectively reviewed to analyze the risk factors of PE and the correlations of PE with the original diseases. RESULTS: Of the 505 patients with PE in the past 20 years, the incidence of PE was increased year by year, especially it increased spectacularly after the year of 2004 [61.2% (309) vs. 38.8% (196)]. It was found to be most prevalent in patients of 4160 years old. Its incidence in males was 1.52 folds higher than that of the females [60.4% (305) vs. 39.6% (200)]. Dyspnea, chest pain and hemoptysis were the initial symptoms in the PE patients. Among the 505 patients, 40.0% of them complained dyspnea with chest pain and hemoptysis. Among them, dyspnea occurred in 100.0% of patients, hemoptysis in 52.1%, and chest pain in 40.0%. In 31.1% of the patients if was complicated with deep venous thrombosis (DVT), 19.8% of them suffering from varicosity, 9.5% of them had the history of surgery less than 30 days before, 22.0% of them suffering from neoplasm, 3.6% of them were accompanied with cerebrovascular disease within 4 days, 17.4% of them were accompanied with infection, 10.1% of them were accompanied with primary pulmonary hypertension, and 16.8% of them were accompanied with heart diseases. Multivariate analysis showed that the history of surgery, DVT and neoplasm had significant correlation with the occurrence of PE [odds ratio (95% confidence interval), OR (95%CI) was 4.540 (2.186-9.443), 0.325 (0.155-0.682), 2.610 (1.020-6.708), P<0.05 or P<0.01], while oral contraception, primary pulmonary hypertension and cerebrovascular disease showed a less significant correlation with the occurrence of PE [OR (95%CI) was 0.297 (0.078-1.126), 3.210 (0.855-12.110), 2.939 (0.862-10.020), all P>0.05]. The age and infection did not show significant correlation with the occurrence of PE [OR (95%CI) was 1.041 (0.674-1.607) and 0.820 (0.410-1.665), both P>0.05]. CONCLUSION: The PE is difficult in diagnosis, but with increasing cognizance, the diagnostic rate of PE has been increased. Patients with history of surgical operation, DVT or neoplasm, who complain dyspnea without known cause, chest pain or hemoptysis, should be subjected to further examinations, as to confirm the diagnosis of PE, then the survival rate of the patients with PE may be elevated.

[Study on the prognosis of patients with acute paraquat intoxication].

OBJECTIVE: To study the correlation factors of acute paraquat intoxication prognosis. METHODS: The early paraquat concentration in plasma and urine, leukocyte count, hepatic and renal function, amylase, electrolyte and the parameters of arterial blood gas were analyzed retrospectively in 111 patients with acute paraquat intoxication. RESULTS: 43 cases (38.7%) of all the 111 patients survived and the other 68 cases (61.3%) died. The patient, whose paraquat concentration was not more than 8.0 µg/ml in plasma and 276.0 µg/ml in urine, could survive. But some patients could die, only if there was no paraquat found in plasma. The paraquat levels in plasma and urine were significantly lower in survivors [(0.82 ± 1.70), (28.12 ± 51.17) µg/ml] than in nonsurvivors [(9.32 ± 12.04), (384.53 ± 597.93) µg/ml, respectively] (P < 0.01). The levels of leukocyte count, serum creatinine, aspartate aminotransferase (AST), and amylase were significantly higher in nonsurvivors than in survivors (P < 0.05, P < 0.01). In addition, metabolic acidosis was easier to appear in nonsurvivors. The multiple logistic regression analysis indicated that the paraquat concentration in plasma and urine, leukocyte count, creatinine and base excess were all related to survival. CONCLUSION: The higher paraquat concentration in plasma and urine, leucocytosis, renal dysfunction and metabolic acidosis are all important factors for the prognosis of paraquat intoxication.

[Studying the therapeutic effects of hemoperfusion with continuous venovenous hemofiltration on the patients with acute paraquat poisoning].

OBJECTIVE: To explore the therapeutic effects of hemoperfusion (HP) with continuous venovenous hemofiltration (CVVH) on the patients with acute paraquat poisoning. METHODS: Ninety-one patients with acute paraquat poisoning were randomly divided into HP group (49 cases) and HP-CVVH group (42 cases). The mortality, survival duration and the death causes between the two groups were compared and analyzed. RESULTS: There were no significant differences in mortality (59.2% versus 61.9%) between the two groups. The mean time between poisoning and death in HP-CVVH group was (4.9 +/- 3.1) days, which was significantly longer than that (3.5 +/- 2.0) days in HP group (P < 0.05). The death proportion on 4th day after poisoning in HP group was 62.1% (18/29), which was significantly higher than that (30.8%, 8/26) in HP-CVVH group (P < 0.05). The hypoxia appeared in 4.3 +/- 2.5 days after poisoning in HP-CVVH group, which was significantly longer than that (3.2 +/- 1.9) days in HP group (P < 0.05). The mortality due to respiratory failure in HP group was 20.4% (10/49), which was significantly lower than that (40.5%, 17/42) in HP-CVVH group (P < 0.05). The incidence of acute renal failure in HP group was 63.3% (31/49), which was significantly higher than that (40.5%, 17/42) in HP-CVVH group (P < 0.05). CONCLUSION: The combined therapy of HP and CVVH can prevent the patients with acute paraquat poisoning from early death and prolong the survival duration, but can not reduce mortality for the patients with acute paraquat poisoning.

Gold interdigitated micro-immunosensor based on Mn-MOF-74 for the detection of Listeria monocytogens.

Accurate and rapid detection of foodborne pathogens is a key to prevent foodborne disease outbreaks. In this study, a novel impedance immunosensor based on a metal-organic framework (Mn-MOF-74) is used to rapidly and sensitively detect Listeria monocytogenes (L. m) in milk. Divalent manganese ions are released by the MOF reduction reaction mediated by hydrogen peroxide. Consequently, the impedance signal was detected by high conductive single-crystalline gold interdigitated microelectrode to achieve quantification of L. m. First, the capture antibodies (Ab1) are modified on the surface of the magnetic beads to generate immunomagnetic beads (MBs@Ab1), which are used specifically to separate L. m cells in the matrices. Later, the immunosensor (Mn-MOF-74@Ab2) is added to the matrices to form a sandwich complex (MBs@Ab1-L. m-Mn-MOF-74@Ab2). Henceforward, Mn2+ is released from the sandwich composite via the action triggered by H2O2. The release of Mn2+ significantly changes the impedance of interdigitated microelectrodes, leading to ultrasensitive detection of L. m. The recoveries for L. m cells at the concentration between 1.0 × 100 and 1.0 × 104 CFU/mL are 90.2%-101.7% in water and 88.5%-96.2% in milk. The detection limit of this approach for L. m cells in water and milk are 7.1 and 9.2 CFU/mL, respectively. This approach can achieve rapid quantification of L. m cells within 60 min, and can also be employed to monitor other foodborne pathogens.

Hafnium oxide layer-enhanced single-walled carbon nanotube field-effect transistor-based sensing platform.

Single-walled carbon nanotube-based field effect transistors (SWCNT-FETs) are ideal candidates for fabricating sensors and have been widely used for chemical sensing applications. SWCNT-FETs have low selectivity because of the environmentally sensitive electronic properties of SWCNTs, and SWCNT-FETs also show a high noise signal and poor sensitivity because of charge trapping from Si-OH hydration of the SiO2/Si substrate on the SWCNTs. Herein, poly (4-vinylpyridine) (P4VP) was used for noncovalent attachment to SWCNTs and selective binding to copper ions (Cu2+). Importantly, the introduction of a hafnium-oxide (HfO2) layer through atomic layer deposition (ALD) overcame the charge trapping by SiO2 hydration and remarkably decreased the interference signal. The sensitivity of the P4VP/SWCNT/HfO2-FET sensor for Cu2+ was 7.9 µA µM-1, which was approximately 100 times higher than that of the P4VP/SWCNT/SiO2-FET sensor, and its limit of detection (LOD) was as low as 33 pmol L-1. Thus, the P4VP/SWCNT/HfO2-FET sensor is a promising candidate for the development of Cu2+-selective sensors and can be designed for the large-scale manufacturing of custom-made sensors in the future.

[Study on the expression of uncoupling protein 2 in the kidney of the rats with hypothyroidism].

OBJECTIVE: To observe the change in the expression of uncoupling protein 2 (UCP2) in kidney mitochondria in rats with hypothyroidism, and study the mechanism of renal injury due to hypothyroidism. METHODS: The Wistar rats were randomly divided into control group (n=10) and hypothyroidism group (n=10). The hypothyroidism rat model was reproduced by low-iodine diet. The intake of iodine in control group and hypothyroidism group were 10.00 µg/d and 1.24 µg/d, respectively. The rats were raised under these conditions respectively for 3 months after they adapted to the feeding for 1 week. Then the thyroid function parameters were measured in blood, and the expressions of UCP2 protein and mRNA in renal tissue were measured by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) methods. RESULTS: The thyrotropic-stimulating hormone (TSH, mU/L) in hypothyroidism group was significantly higher than that in control group (4.88±1.37 vs. 1.65±0.33, P<0.05). The levels of total triiodothyronine (TT(3)), total thyroxine (TT(4)), free triiodothyronine (FT(3)) and free thyroxine (FT(4)) in serum in hypothyroidism group were significantly lower than those in control group [TT(3) (nmol/L) : 0.54±0.07 vs. 0.98±0.17, TT(4) (nmol/L): 7.82±2.18 vs. 48.78±3.65, FT(3) (pmol/L): 2.28±0.22 vs. 2.99±0.10, FT(4) (pmol/L): 11.38±1.74 vs. 29.27±0.95, all P<0.01]. The immunohistochemistry study revealed that the UCP2 protein expression in both renal glomeruli and tubule tissues in the hypothyroidism group was significantly lower than that of control group (renal glomeruli: 0.17±0.02 vs. 0.24±0.04, renal tubule: 0.19±0.02 vs. 0.25±0.02, both P<0.01). The RT-PCR showed that the UCP2 mRNA expression in the hypothyroidism group was significantly lower than that of control group (0.70±0.19 vs. 1.30±0.09, P<0.01). CONCLUSION: Hypothyroidism may produce damage to kidney, which is related to the down-regulation of UCP2 expression in the mitochondria of renal cells.

Ziyin Bushen Decoction Alleviates Perimenopausal Syndrome in Rats by Enhancing Estradiol Production.

Perimenopausal syndrome (PMS) has a high incidence rate and affects the physical and mental health of middle-aged and elderly women. The blockage of PMS is significant in improving the health of perimenopausal women. Currently, for PMS prevention and treatment, traditional Chinese medicine (TCM) has become an ideal choice because of its safety and effectiveness. This study aimed to explore the anti-PMS effects of Ziyin Bushen Decoction (DKTP) and the underlying mechanism. Thirty female Wistar rats were divided into 5 groups (n = 6): control group, low-dose DKTP group, medium-dose DKTP group, high-dose DKTP group, and nilestriol group. The estradiol (E2) level in rat peripheral blood was analyzed using an E2 Radioimmunoassay Kit, and uterine morphologic changes were examined by hematoxylin-eosin staining. Learning and memory ability of rats was assessed by Morris water maze (MWM) and novel object recognition (NOR) task. E2 synthesis, metabolism, and transport associated estrogen receptor-alpha (ERα), GnRHR, CYP17, CYP11A1, CYP19, 17ßHSD, STS, and SHGB were assessed to explore the E2-promoting mechanism of DKTP during PMS treatment. The loss of learning and memory, the decreased estrous and uterine coefficient, and the presence of histopathological changes suggests a successful establishment of rat PMS model. Following DKTP or nilestriol treatment, the above results were reversed. E2 level in serum, uterine, and ovarian tissues was upregulated upon different concentrations of DKTP treatment, indicating that DKTP promotes the E2 level in a dose-dependent manner. DKTP also increased the expression of ERα, CYP17, CYP11A1, CYP19, 17ßHSD, STS, and SHGB while decreased the GnRHR expression in uterine and ovarian tissues, revealing that these key molecules involved in estrogen synthesis, metabolism, and transport in PMS rats. We confirmed the anti-PMS effect of DKTP through enhancing E2 production. Exploring a novel drug based on improving E2 synthesis, metabolism, and transport may represent a novel strategy for PMS prevention and treatment.

Passivation of black phosphorus as organic-phase enzyme platform for bisphenol A determination.

Black phosphorus (BP) has a high charge-carrier mobility (∼1000 cm2 V-1 s-1), but the bare BP degrades rapidly in the presence of oxygen and water which limits the application of the BP. In this study, a simple, non-covalent passivation strategy is developed by modifying of the BP with hexamethylendiamine (HA). The functionalized BP exhibits good stability over 4 weeks. The organic phase interdigital electrode which is constructed by stable HA/BP and tyrosinase displays lowest noise signal (0.025 nA) and relatively low detection limit (10 nmol L-1) for bisphenol A. This work provides a new strategy for construction of novel biofuel cell, bioelectronics and biosensors.

A new aptamer/black phosphorous interdigital electrode for malachite green detection.

Malachite Green (MG), a cationic triphenylmethane dye, has adverse effects on the immune and reproductive system. Thus, it is essential to develop a rapid, sensitive and high-selective method for determination of MG. Black phosphorus (BP) has high charge-carrier mobility (∼1000 cm2 V-1 s-1) and high adsorption capacity for cationic dyes (i.e. MG) through both electrostatic and hydrophobic interactions. Thus, it potentially plays as a high-sensitive sensing platform for detecting MG. However, BP degrades within 12 h under humid condition, which limits its applications. To overcome this issue, cysteine (CYS) is used for protecting BP from oxidation and ceasing its degradation. To the best of our knowledge, it is the first time that CYS is used to functionalize BP, and a silicon interdigital electrode is fabricated with the functionalized BP and aptamer. The BP-based interdigital electrode shows a lowest detection limit of 0.3 ng L-1 toward MG. This work provides a new route to prepare a large scale and selective biosensor for MG monitoring on site in future.

Supramolecular Self-Assembly of Perylene Bisimide-Based Rigid Giant Tetrahedra.

Recently, ordered structures constructed from rigid three-dimensional (3D) shaped polyhedra have been drawing general interest, with the tetrahedron being the simplest one but showing complicated assembly behaviors. Rigid tetrahedron building blocks have been shown to form quasicrystalline and crystalline phases with high packing fractions by both simulation and experiments. Nevertheless, the study of 3D tetrahedral building blocks is limited, especially in the field of supramolecular self-assembly. Here, we present an experimental study of rigid giant tetrahedral molecules constructed by attaching four bulky polyhedral oligomeric silsesquioxane (POSS) cages to a tetrahedral perylene bisimide (PBI) scaffold. Self-assembly of these giant tetrahedra is mediated by π-π interaction between the tetrahedral PBI-based scaffolds and their overall tetrahedral symmetry. A monolithic nearly centimeter-sized hexagonal supramolecular structure was observed in the giant tetrahedron with short flexible linkers between PBI and POSS cages, while a micrometer-sized crystalline helical structure formed in that with completely rigid aromatic linkers. Their significant difference in electrical conductivity could be explained by two completely different packing models of the giant tetrahedra.