1.Micro Potentiometric Label-free Immunosensor for Glycated Hemoglobin
Chao BIAN ; Qiannan XUE ; Jizhou SUN ; Hong ZHANG ; Shanhong XIA
Chinese Journal of Analytical Chemistry 2010;38(3):332-336
A miniaturized potentiometric label-free immunosensor based on the standard complementary metal-oxide-semiconduction transistor(CMOS) process and micro fabrication technique was developed to monitoring diabetes, which could detect the concentrations of glycated hemoglobin (HbA1c) and hemoglobin. This immunosensor includes a micro field-effect transistor based sensor chip integrated with signal readout circuit and a disposable probe electrode. The micro sensor chip was designed by our lab and fabricated by Chartered Semiconductor, Singapore. The disposable probe electrode, which was integrated with sensitive electrodes array and micro reaction pool, was deposited on polyester plastic based on micro fabrication techniques. Antibody of HbA1c and hemoglobin were immobilized on the electrode based on self assemble monolayer and gold nanoparticles. The characteristics of the electrode during modification were studied by cyclic voltammetry and electrochemical impedance technique. The response characteristic of the immunosensor was detected. HbA1c from 4 to 24 mg/L and hemoglobin from 60 to 180 mg/L can be detected by this immunosensor.
2.A Fiber-Optic Sensor Based on Plasmon Coupling Effects inGold Nanoparticles Core-Satellites Nanostructures for Detection of Mercury Ions
Shuo JIA ; Chao BIAN ; Jianhua TONG ; Jizhou SUN ; Shanhong XIA
Chinese Journal of Analytical Chemistry 2017;45(6):785-790
Based on the plasmon coupling effect in gold nanoparticles core-satellite nanostructures linked by thymine(T)-rich DNA hybridization and the specific Hg2+-mediated T-Hg2+-T base pair, a novel localized surface plasmon resonance (LSPR) optical fiber sensor was proposed and developed for Hg2+ detection in water.The Hg2+-induced conformational change in T-rich DNA sequence inhibited the DNA hybridization reaction, weakened the plasmon coupling effect and leaded to the change of LSPR resonance wavelength.The concentration of Hg2+ was quantitatively determined by the resonance wavelength redshift.The linear range of Hg2+ detection was about 5-150 nmol/L with LOD about 3.4 nmol/L.The specificity of the sensor was proved great by evaluating the response to other heavy metal ions such as Zn2+, Mg2+, Pb2+ and so on.This sensor was applied in environmental water detection by standard addition method,with the RSD less than 4.8% and recoveries of 94.2%-105.4%.
3.Laparoscopic colorectal resection combined with simultaneous radiofrequency ablation for liver metastases
Feng YANG ; Zhan LIU ; Yuntao LI ; Kang HOU ; Shanhong JIANG ; Xiang XIA
Chinese Journal of Digestive Surgery 2009;8(1):27-29
Objective To assess the clinical value of laparoscopic colorectal resection combined with simultaneous radiofrequency ablation for liver metastases.Methods Twenty-two patients with colorectal cancer and synchronous liver metastases were treated by laparoscopie colorectal resection and simultaneous radiofrequency ablation(RFA)in Third People's Hospital of Chengdu from December 2001 to July 2006.Areas of colliquative necrosis were detected by contrast-enhanced computed tomography postoperatively.The outcomes were analyzed by chi-square test.Results Of all patients,8 had muhiple liver metastases,16 had complications.Thirty-one liver metastases were treated by RFA,and no complication oecurred.The mean postoperative hospital stay was(14±5)days,and there was no perioperative death.Five of the 22 patients were identified as incomplete ablation of the tumor,and the RFA was reperformed.The recurrence of liver metastases in the RFA necrotic zone was observed in 4 patients,and RFA was reperformed on 2 of them.Six patients died,and 2 of them died of liver metastases recurrence in the RFA necrotic zone.The recurrence rate of liver metastases and mortality was 18%(4/22)and 27%(6/22),respectively.The recurrence rate of patients with the diameter of the metastatic lession≥2.0 cm was significantly higher than those with the diameter of the metastatic lession<2.0 cm(x2=5.867,P<0.05).Conclusions Laparoseopie colorectal resection combined with simultaneous RFA provide a curative opportunity for colorectal cancer patients who are old and have multiple liver metastases,complications,poor tolerance of operation,and for patients whose tumors are difficult to resect.
4.A Micro Electrochemical Sensor for Nitrate Determination Based on Square_wave Pulsating Current Deposition Process
Yang LI ; Jizhou SUN ; Jinfeng WANG ; Chao BIAN ; Jianhua TONG ; Hanpeng DONG ; Hong ZHANG ; Shanhong XIA
Chinese Journal of Analytical Chemistry 2015;(1):98-104
Based on microfabrication technology and electrochemical modification method, a micro electrochemical sensor for nitrate ( NO-3 ) determination was developed. A micro sensor chip with working electrode and counter electrode was used as the signal convertor of the sensor. The area of the micro working_electrode was only 1 mm2 . As an electrocatalysis sensitive material, copper was electrodeposited onto the working electrode by square_wave pulse current electrodeposition method. The morphologies and components of freshly deposited materials were examined by scanning electron microscopy ( SEM ) and X_ray diffraction ( XRD) to explore key factors that affected the electrocatalytic ability of the deposited copper layer for reducing nitrate ions. The experimental results revealed that under the optimal conditions, the deposited copper layer was macroporous and had a larger effective surface area that could serve as a more effective electrocatalyst in facilitating nitrate reduction. Electrochemical response of the macroporous copper layer was characterized by linear sweep voltammetry in acidic supporting electrolytes ( pH=2 ) . The electroanalytical results showed that the modified microsensor had marked sensitivity for standard nitrate samples within the concentration range from 12. 5 to 3000 μmol/L (in the range of 12. 5-200 μmol/L yielded straight line:y1=-0. 1422x-10. 326, R12=0. 9976, while in the range of 200-3000 μmol/L yielded straight line: y2=-0. 0984x-22. 144, R22=0. 9927) with a detection limit of 2 μmol/L (S/N=3). The developed electrochemical microsensor was also employed for nitrate determination in water samples collected from lakes and rivers near the city of Beijing. The results were in good agreement with the data given by qualified water quality detection institute, with the deviations from 3 . 9% to 15 . 4%.
5.Clinical study on transjugular intrahepatic portosystemic shunt in treatment of portal hypertension of patients with hepatocellular carcinoma
Hao LI ; Guohong HAN ; Zhanxin YIN ; Jianhong WANG ; Shanhong TANG ; Xingshun QI ; Jie LIU ; Jielai XIA ; Kaichun WU ; Daiming FAN
Chinese Journal of Digestion 2010;30(5):293-295
Objective To evaluate the therapeutic efficacy and safety of transjugular intrahepatic portosystemic shunt (TIPS) for the treatment of portal hypertension of patients with hepatocellular carcinoma.Methods Ninety-five portal hypertension patients with hepatic carcinoma were enrolled.TIPS was performed in 63 patients and the other 32 patients received support medical care.The data referred to survival time of the 95 patients after treatment was collected by follow-up visit.The informations about success rate of TIPS,hepatic encephalopathy,rebleeding and causes of death were assessed.The Kaplan-Meier method was used to compare the survival time between two groups.The association of survival time with Child-Pugh classification and model for end-stage liver disease (MELD) score was analyzed.Results The success rate of TIPS was 97.8% with reduction of mean portal vein pressure of 13.6 cmH2O(1 cmH2O=0.098 kPa).The incidence of hepatic encephalopathy was 20.6% and rebleeding was 26.3% six months after TIPS treatment.Fifty-six patients treated with TIPS died at the end of follow-up.Twelve of which were died of variceal bleeding complicated with portal hypertension.The median survival time of TIPS group (3.67 months) was significantly longer than that of control group (1 month). Moreover, the median survival time in patients with low MELD score (≤13) was significantly longer than that in those with high MELD seore (>13, x2=4.71,P=0.03). Whereas the median survival time was decreasing from Child-Pugh A to C(x2=15.6,P=0.00). Conclusions TIPS is one of effective and safe therapeutic methods to control portal hypertension. However, liver function is an important factor for selcetion of TIPS.