Kaur Gurpreet, Tomar Monika, Gupta Vinay
Department of Physics and Astrophysics, University of Delhi, Delhi, 110007, India.
Physics Department, Miranda House, University of Delhi, Delhi, 110007, India.
Anal Bioanal Chem. 2017 Mar;409(8):1995-2005. doi: 10.1007/s00216-016-0147-z. Epub 2017 Jan 11.
Nanostructured nickel oxide (NiO) thin film has been explored as a matrix to develop a reagentless biosensor for free and total cholesterol as well as low density lipoprotein (LDL) detection. The redox property of the matrix has been exploited to enhance the electron transfer between the enzyme and the electrode as well as to eliminate the toxic mediator in solution. X-ray diffraction, scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy were carried out to characterize the NiO thin film. Biosensing response studies were accomplished using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). The developed biosensors exhibited a high sensitivity of 27 and 63 μA/mM/cm over a linear range of 0.12-10.23 and 1-12 mM, respectively, for free and total cholesterol. Reagentless estimation of LDL was also achieved over the wide range 0.018-0.5 μM with a sensitivity of 0.12 mA/μM/cm. The results are extremely promising for the realization of an integrated biosensor for complete detection of cholesterol in the serum samples. Graphical Abstract Reagentless sensing mechanism of (a) free cholesterol and (b) total cholesterol using nanostructured NiO matrix.
纳米结构的氧化镍（NiO）薄膜已被探索用作一种基质，以开发一种用于检测游离胆固醇、总胆固醇以及低密度脂蛋白（LDL）的无试剂生物传感器。利用该基质的氧化还原特性来增强酶与电极之间的电子转移，并消除溶液中的有毒媒介物。通过X射线衍射、扫描电子显微镜、原子力显微镜和傅里叶变换红外光谱对NiO薄膜进行了表征。使用循环伏安法（CV）、电化学阻抗谱（EIS）和差分脉冲伏安法（DPV）完成了生物传感响应研究。所开发的生物传感器对游离胆固醇和总胆固醇分别在0.12 - 10.23 mM和1 - 12 mM的线性范围内表现出27和63 μA/mM/cm的高灵敏度。在0.018 - 0.5 μM的宽范围内也实现了对LDL的无试剂检测，灵敏度为0.12 mA/μM/cm。这些结果对于实现用于完整检测血清样本中胆固醇的集成生物传感器极具前景。图形摘要 使用纳米结构NiO基质对（a）游离胆固醇和（b）总胆固醇的无试剂传感机制。
