本文選題：乙醇 + 多壁碳納米管　； 參考：《重慶醫(yī)科大學(xué)》2011年碩士論文

【摘要】：目的 在醫(yī)學(xué)、法醫(yī)學(xué)、食品安全檢測、環(huán)境等領(lǐng)域,C_2H_5OH的測定都具有重要的意義。尤其隨著經(jīng)濟(jì)的發(fā)展,醉酒駕駛逐漸增多,故血液中酒精濃度的定量快速檢測的意義日益重要。電化學(xué)生物傳感器檢測法由于具有較高的靈敏度,較寬的線性范圍,快速的響應(yīng)時間而逐漸成為血液中酒精含量測定方法研究的熱點(diǎn)。 MWCNTs是一種納米級的兼具有金屬性和半導(dǎo)體性的材料。該材料具有導(dǎo)電性強(qiáng)、較大的比表面積和良好的電催化活性,是一種被廣泛采用的電子傳遞媒介體。在電化學(xué)生物傳感器電活性物質(zhì)的電子傳遞過程中已被證實(shí)效果顯著。PB納米粒子具有的納米級尺寸效應(yīng),同時可降低氧化還原物質(zhì)尤其是過氧化物電化學(xué)反應(yīng)的過電位;PB結(jié)構(gòu)穩(wěn)定,并具有優(yōu)越的催化活性和良好的電子可逆?zhèn)鬟f效應(yīng)。ITO電極是鍍有氧化銦錫薄膜的一種電極。其化學(xué)性質(zhì)穩(wěn)定、易于制得,同時具有導(dǎo)電性和催化性。本實(shí)驗(yàn)利用羧基化的多壁碳納米管(MWCNTs)修飾氧化銦錫(ITO)電極,并在其表面吸附一層納米普魯士藍(lán)(PB)顆粒作為電子介體制作一種新型的乙醇傳感器。通過該方法實(shí)現(xiàn)了對乙醇的直接電化學(xué)催化,并放大電響應(yīng)信號,從而為建立一種新的檢測血中C_2H_5OH電化學(xué)方法奠定了基礎(chǔ)。 方法 (1)將ITO玻璃切割均勻,制備成ITO條形電極。 (2)將5mg純化的多壁碳納米管超聲分散在50mL N,N-二甲基甲酰胺(DMF)中。超聲處理10 min,制備成1.0mg/mL的MWCNTs分散懸浮液。取20μL分散液滴涂于ITO電極上(0.6×0.6cm~2),得到碳納米管修飾電極(MWCNT/ITO)。然后在PBS(pH=7.0)緩沖溶液中循環(huán)伏安掃描,分析修飾了MWCNTs的ITO電極的性能。 (3)將5mmol/L K_3Fe(CN)_6溶液100mL在磁力攪拌下緩慢加入到100mL 5mmol/L FeCl_3(pH=1)中,攪拌3h得到Nano-PB膠體溶液。然后將前期制備好的MWCNTs/ITO電極浸泡在納米PB溶液中,通過靜電吸附,在MWCNTs/ITO電極表面形成均勻的納米PB膜。將該復(fù)合電極分別在PBS和PBS+C_2H_5OH溶液中采用循環(huán)伏安法掃描,考察制備的電極的最優(yōu)性能和測試條件。 (4)通過采用氣相色譜法測定血液中乙醇濃度進(jìn)行平行比較,測定MWCNTs/PB/ITO復(fù)合電極的性能。 結(jié)果 在ITO電極上自組裝一層MWCNTs,然后通過靜電吸附修飾上一層納米普魯士藍(lán)膜,制備出性能良好的乙醇生物傳感器。所制備傳感器對乙醇具有明顯的電化學(xué)活性,線性范圍為0.5～10mmol/L,在S/N=3的情況下,檢出限為0.07mmol/L(R=0.9968),達(dá)到95%穩(wěn)態(tài)響應(yīng)時間約為15s。 將MWCNTs/ITO電極浸入納米普魯士藍(lán)溶液中,分別在2、4、8、16小時后取出。并將制備好的不同MWCNTs/PB/ITO復(fù)合電極分別在0.02mol/L的PBS溶液中采用循環(huán)伏安法掃描,其電流響應(yīng)值隨浸泡時間的增加而逐漸增大,在達(dá)到8小時后變化趨于平穩(wěn)。同時將優(yōu)化好的復(fù)合電極分別在不同溫度、pH值及掃描速率中進(jìn)行考察,得出該復(fù)合傳感器在室溫25攝氏度、pH=7.0的條件下以50mv/s的速率掃描為最優(yōu)化條件。 用此法制備的C2H5OH電化學(xué)生物傳感器具有較高的催化活性,較低的檢測限,較快的檢測速度,將該電化學(xué)生物傳感器用于C_2H_5OH的實(shí)際檢測,結(jié)果令人滿意。 結(jié)論 本實(shí)驗(yàn)首先在ITO電極上自組裝一層MWCNTs,然后通過靜電吸附修飾一層納米普魯士藍(lán)復(fù)合膜,制備出新型的C_2H_5OH電化學(xué)生物傳感器。該傳感器制作方法簡單、可靠,催化性能良好,檢測時間快速,檢測結(jié)果基本準(zhǔn)確,具有良好的應(yīng)用發(fā)展前景。
[Abstract]:Purpose


In the fields of medicine , forensic medicine , food safety detection , environment and so on , the determination of C _ 2H _ 5OH is of great significance . Especially with the development of economy , the importance of quantitative rapid detection of alcohol concentration in blood is becoming more and more important .


MWCNTs is a kind of nano - scale material with both metallic and semiconducting properties . The material has strong electrical conductivity , larger specific surface area and good electrocatalysis activity . It is a widely used electron transfer medium . It has been proved to be a kind of electrode of indium tin oxide film .


method


( 1 ) cutting the ITO glass evenly to prepare an ITO strip electrode .


( 2 ) 5 mg of purified multi - walled carbon nanotubes were ultrasonically dispersed in 50 mL of N , N - dimethylformamide ( DMF ) . Ultrasonic treatment was performed for 10 min to prepare 1.0 mg / mL MWCNTs dispersion suspension . 20 渭L of dispersed droplets were applied to ITO electrodes ( 0.6 脳 0.6cm ~ 2 ) to obtain carbon nanotube modified electrode ( MWCNT / ITO ) . The performance of ITO electrode modified MWCNTs was analyzed by cyclic voltammetry scanning in PBS ( pH = 7.0 ) buffer solution .


( 3 ) The solution of 5mmol / L K _ 3Fe ( CN ) _ 6 was slowly added to 100 mL of 5 mmol / L FeCl3 ( pH = 1 ) under magnetic stirring and stirred for 3 h to obtain the Nano - PB colloidal solution . The MWCNTs / ITO electrode prepared in the earlier stage was immersed in the nano - PB solution , and a uniform nano - PB film was formed on the surface of MWCNTs / ITO electrode by electrostatic adsorption . The optimal performance and test conditions of the prepared electrode were investigated by cyclic voltammetry scanning in PBS and PBS + C _ 2H _ 5OH solution .


( 4 ) The performance of MWCNTs / PB / ITO composite electrode was determined by comparing the concentration of ethanol in blood by gas chromatography .


Results


In the presence of S / N = 3 , the detection limit is 0.07 mmol / L ( R = 0.9968 ) , and the steady - state response time of 95 % is about 15 s .


The MWCNTs / ITO electrodes were immersed in the solution of nano - pruculine blue , and then taken out after 2 , 4 , 8 and 16 hours respectively . The prepared MWCNTs / PB / ITO composite electrode was scanned in 0.02mol / L PBS solution . The current response value of MWCNTs / ITO electrode was gradually increased with the increase of immersion time . At the same time , the optimized composite electrode was scanned at different temperature , pH value and scanning rate , and the optimized composite electrode was scanned at 50 mv / s at room temperature at 25 鈩，

本文編號：1753704