MicroRNA-17 (miR-17) is a critical biomarker linked to various cancers and diseases, underscoring the need for sensitive and selective detection methods. Herein, an ultra-sensitive electrochemiluminescent (ECL) sensor for miR-17 detection utilizing MOF-derived porous CuFe2O4 nanospheres and CRISPR/Cas13a trans-cleavage-triggered hybridization chain reaction (HCR) amplification was presented. The porous CuFe2O4 nanospheres possessed a high surface area and excellent catalytic activity, significantly enhancing ECL emission. To the best of our knowledge, this is the first report demonstrating that MOF-derived CuFe2O4 can effectively enhance the electrochemiluminescence of Ru(bpy)32+ for miR-17 detection. The CRISPR/Cas13a system provided miR-17 recognition and trans-cleavage activity, triggering HCR for signal amplification. Under optimized conditions, the biosensor exhibited a wide linear detection range from 20 aM to 5000 aM, with a detection limit of 9.23 aM. The system discriminated miR-17 from closely related miRNAs with negligible cross-reactivity, which demonstrated its outstanding selectivity. Practical applicability was confirmed by successful quantification of miR-17 in diluted human serum which achieved recovery rates between 95.2% and 104.8%. The results validated the biosensor's potential for early disease diagnosis and clinical monitoring of miR-17-associated disorders.

The electrochemical behaviors of CFD (ceftazidime) at a graphene modified electrode (Gr/GCE) were investigated by cyclic voltammetry. Compared with a bare glassy carbon electrode, the Gr/GCE exhibited a significantly enlarged irreversible oxidation peak due to the excellent electron transfer function and catalytic effect of graphene. The peak currents were proportional to CFD concentration of 0.25 similar to 10.0 mu M and 10.0 similar to 75.0 mu M, with the detection limit of 0.1 mu M. Furthermore, the interaction between CFD and double stranded DNA was studied by electrochemical and fluorescence methods. The results showed that the peak current of CFD decreased remarkably and the fluorescence intensity quenched significantly with the increasing of DNA concentration, which indicated that the CFD molecule intercalated into DNA to form a CFD-DNA complex. In addition, the number of electrons transferred in the electrochemical reaction was calculated based on the electrochemical results to assess the possible interaction mechanisms.

采用循环伏安法聚合精氨酸制备得到乙酰氨基酚印迹膜修饰电极(GCE).考察了不同聚合条件进行探究,从而确定最佳聚合条件对乙酰氨基酚(ACOP)进行测定.结果表明,该印迹电极对ACOP具有较好的检测效果,在4.0×10-6～9.09×10-5 mol/L范围内与其氧化峰电流呈一定的线性关系,最低检测浓度为8.0×10-7 mol/L.将此电极用于实际样品中ACOP的检测,回收率分别为98.1％、104.1％、102.0％.

An electrochemical sensor for the determination of nitrite was successfully fabricated via electro-depositing Au nanoparticles on a glassy carbon electrode (GCE) modified with MoS2 nanosheets. The morphology and composite of the resulted electrode were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The modified processes of the nanoAu-MoS2/GCE were monitored by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The amperometric current–time (i–t) showed that the developed electrode had excellent response for sodium nitrite under the optimum conditions, and the oxidative current of sodium nitrite was proportionally correlated with its concentration (10–2100 μM) with a limit of detection (LOD) of 0.09 μM (S/N = 3), which can be employed in the determination of nitrite in river and drinking water with the advantages of good reproducibility, anti-interference, long-term stability and satisfactory recovery rate.

An electrochemical sensor for determination of ceftazidime (CFD) was fabricated by polymerizing crystal violet (PCV) and platinum nanoparticles (nanoPt) on a glassy carbon electrode (GCE). The nanoPt/PCV composite film exhibited excellent catalytic performance toward CFD. On this modified electrode, the CFD had an irreversible oxidation peak at 0.8 V with a dramatically amplified current value. The electrochemical behaviors of CFD and the conditions that may affect these behaviors were investigated detailedly on the nanoPt/PCV/GCE. Under the optimized conditions, the sensor showed a wide linear range over the concentration of CFD from 0.25 to 10 mu M. The detection limit was 0.01 mu M. The sensor can be applied for detecting the content of CFD in meat samples with good selectivity and stability. The recovery was between 97.8% and 103%.

The blended teaching mode based on network platform has become an important content of teaching reform in colleges and universities, and the application of this mode to the course of "Instrumental analysis"has changed the role of teachers and students,combined the leadership of teachers and main role of students effectively.According to this mode, students study knowledge through network platform before class;report what they learned and communicate in class by group form;consolidate knowledge after class.Unquestionably, this contributes to develop student 's ability of autonomous learning, logical thinking, cooperation and communication,which meet the social demand for talents.At the same time,higher requirements for teachers' ability and quality are put forward.

以测定电极的可逆性实验为例,介绍了电化学工作站CHI660D在仪器分析实验教学中的应用,旨在拓展电化学工作站在本科教学中的应用范围,促进实验教学的改革.

以高效液相色谱法测可乐中咖啡因的含量为例,介绍了Origin作图软件在仪器分析实验数据处理中的应用,有助于提高学生的学习能力.

Based on a sol-gel procedure, a molecularly imprinted polymer (MIP) for 2, 4-dichlorophenoxyacetic acid (2, 4-D) was synthesized, using phenyltrimethoxysilane (PTMOS), aminopropyltriethoxysilane (APTES) as monomers and tetraethoxysilane (TEOS) as cross-linking agent. In addition to the amount of the template, some factors in the sol-gel process: TEOS/APTES/PTMOS molar ratio, H2O/Si molar ratio, CH3CH2OH/Si molar ratio, etc. were investigated in detail. Results show that the optimum conditions for the preparation of the MIPs were 20:1.5:1 (TEOS: APTES: PTMOS), ca. 4 (H2O/Si), ca. 4 (CH3CH2OH/Si), respectively. Effects of various parameters involved in the adsorption process of 2, 4-D on MIP such as incubation time, pH, etc. were also evaluated. It is found that the adsorption attained equilibrium within 3 h, the optimum pH for adsorption was about 7 and the adsorption obeyed Langmuir model. Test results also demonstrated that the present MIP for 2, 4-D had large adsorption capacity (the maximum adsorption concluded from Langmuir model reached 243.3 mg/g) and good selectivity.

The Leucine and silver composite film modified glassed carbon electrod(Ag - Leu/ GCE)was prepared. The modified electrod showed an excellent electrocatalytical effect on the oxidation of NE. Under the optimized experimental conditions,linear relationship between values of peak current and concentration of NE was ranged from 2. 4 × 10 - 7 mol/ L to 4. 8 × 10 - 5 mol/ L with detection limit of 1. 2 × 10 - 7 mol/ L. The proposed method was used in the determination of NE in medicine,giving values of recovery in the range of 97. 5% ~ 101. 3% .

A method was established for the determination of the content of Vitamin C in peach juice by HPLC. An Agilent C18 column was used and the flow phase was a mixture of 0.05mol/L KH2PO4∶methanol=96∶4(v/v). The flow rate was 0.6mL/min, and the detection wavelength 288nm. The standard working curve of Vitamin C had a good linear relation between concentration and peak area in the concentration range of 5-80μg/mL,the linear equation was y=11.2471x-16.6383,the related coefficient (r)was 0.9989,and the relative standard deviation 1.49%. Being simple,fast,accurate and stable,the method is suitable for determining the content of Vitamin C in fruits,vegetables and beverages.

A new method of detecting the content of caffeine in cola by using HPLC is established.The detection wavelength is 286 nm,with the deionized water and methanol in a volume of 5:5 as the flowing phase,the flowing speed is 0.8 mL/min.Caffeine and the peak area.has a good linear relation in the concentration range of 10～50μg/mL.The relatively standard deviation is 0.64%.The method is accurate,simple,rapid and suitable for the determination of caffeine in cola drinks.

Using ultra-fluorine ion selective electrode method for fluorine content in black tea,green tea two kinds of tea were measured and studied some factors influencing the determination results.Results fluorine content in black tea,green tea were 120.70 and 106.57 mg/kg less than China’s agriculture industry standard,the determination method of standard addition recovery was 93.50 %~109.60 %.Results showed that ultrasonic-fluorine ion selective electrode method simple operation,high energy recovery of the sample is meet for tea.

为了简便、快速测定维C银翘片中维生素C的含量,样品中还原型维生素C氧化为脱氢型维生素C,脱氢型维生素C水解生成2,3-二酮古乐糖酸,然后与2,4-二硝基苯肼耦联反应生成较稳定的脎,然后通过分光光度计测定三种维C银翘片中的维生素C含量。结果表明：维生素C在1～12 mg/L浓度范围内与吸光度呈良好的线性关系说明此方法测定的结果准确可靠。

The standard curve method was measured in the fluorine content in the reunification of green tea,by adding TISAB buffer solution to control the measurement conditions.The experiment was based on the high selectivity of fluorine ion selective electrode for fluorine ion.And in the experiment the determination influence affected by mixer response time,TISAB buffer and blank value are discussed.The experimental results show that the fluoride content was 1.77 mg / L,recoveries were 96.4% and 106.5%.The Simple apparatus,the method is simple,high recovery and the results are reliable,able to meet the determination of green tea samples.

A method has established for the detection of Vitamin C(Vc) in orange juice by high performance liquid chromatography(HPLC).The LC-100PLUS HPLC system with Agilent TC-C18 column(4.6×250 mm,5 μm) was used.The samples were analyzed using 0.05 mol/L potassium dihydrogen phosphate: methanol(V:V=96:4) as mobile phase with the flow rate of 0.6 mL/min.The temperature of the column was room temperature and the detection wave length was 288 nm.The standard working curve of Vc and peak area had a good linear relation between the concentration from 5 ?g/mL to 80 ?g/mL.The linear equation was y=11.2534 x-17.0162and the related coefficient equaled to 0.9989.The relative standard deviation of this method was 1.40 %.This method proved to be a simple,rapid,exact and reliable way to determine the content of Vitamin C in most of the beverages.

Hexadecyl trimethyl ammonium Bromide(CTAB)modified zeolite was prepared and used as an adsorbent for Congo red in aqueous solution.Adsorption capacities of modified zeolite for Congo red is much larger than that of non-modified zeolite.The adsorption properties were studied.Finally,adsorption model was applied to the adsorption,and the datas obeyed Langmuir adsorption isotherm.