Bhupat and Jyoti Mehta School of Biosciences, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, India.
Bhupat and Jyoti Mehta School of Biosciences, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036, India.
Biochim Biophys Acta Gen Subj. 2017 Jun;1861(6):1559-1565. doi: 10.1016/j.bbagen.2017.01.001. Epub 2017 Jan 4.
Biosensing of NADH on bare electrodes has drawbacks such as high over-potential and poisoning during the oxidation reaction. To overcome this challenge a different approach has been undertaken by incorporating neutral red (NR) in Al doped ZnO (AZO) thin films using one-pot chemical bath deposition (CBD). The surface morphology of the films was hexagonal nanorods along the c-axis, perpendicular to the substrate. The thickness of the thin films were ranging from 400 to 3000nm varying dependent on time of deposition (30 to 150min). The average diameter of the nanorods was larger in the presence of neutral red (NR-AZO) with ~300nm in contrast to its absence (AZO) with ~200nm. The density of the packing of nanorods was dependent on the citrate concentration used during deposition. Control over the dopant concentration in the films was achieved by varying the area of Al foil used in the deposition solution. The selected area diffraction (SAED) and X-ray diffraction (XRD) indicated 002 plane of orientation in the nanorods. FTIR and FT-Raman analysis revealed conserved structure of NR and AZO. Chronoamperometric (CA) analysis showed a sensitivity of 0.45μAcmmM and LoD of 22μM within the range 0.075-4mM of NADH. The biological sensing of NADH was validated by physical adsorption of NAD dependent-lactate dehydrogenase (LDH) on NR-AZO. CA showed sensitivity of 0.56μAcmmM and LoD for lactate was 27μM in the range of 0.1-1mM of lactate. Further validation with real-time serum sample shows that LDH/NR-AZO correlates with the clinical values. The distinction in this study is that the organic mediator like neutral red has been incorporated into the grain structure of the ZnO thin film whereas other study with the mediators have only attempted surface functionalization. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editor: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader.
裸电极对 NADH 的生物传感存在一些缺点，例如氧化反应过程中的高过电势和中毒。为了克服这一挑战，一种不同的方法已经被采用，即在掺铝氧化锌（AZO）薄膜中加入中性红（NR），使用一锅化学浴沉积（CBD）法。薄膜的表面形貌为沿 c 轴的六方纳米棒，垂直于基底。薄膜的厚度从 400 纳米到 3000 纳米不等，取决于沉积时间（30 到 150 分钟）。在存在中性红（NR-AZO）的情况下，纳米棒的平均直径较大，约为 300nm，而在不存在中性红（AZO）的情况下，纳米棒的平均直径较小，约为 200nm。纳米棒的堆积密度取决于沉积过程中使用的柠檬酸浓度。通过改变沉积溶液中铝箔的面积，可以实现对薄膜中掺杂浓度的控制。选区电子衍射（SAED）和 X 射线衍射（XRD）表明纳米棒具有 002 面取向。傅里叶变换红外（FTIR）和傅里叶变换拉曼（FT-Raman）分析表明，NR 和 AZO 的结构保持不变。计时安培（CA）分析显示，在 0.075-4mM 的 NADH 范围内，NADH 的灵敏度为 0.45μAcmmM，检测限为 22μM。通过 NAD 依赖的乳酸脱氢酶（LDH）在 NR-AZO 上的物理吸附验证了 NADH 的生物传感。CA 显示，在 0.1-1mM 的乳酸范围内，乳酸的灵敏度为 0.56μAcmmM，检测限为 27μM。用实时血清样本进行的进一步验证表明，LDH/NR-AZO 与临床值相关。本研究的区别在于，有机介质如中性红已被掺入 ZnO 薄膜的晶粒结构中，而其他使用介质的研究仅尝试了表面功能化。本文是题为“生物纳米材料的最新进展”的特刊的一部分，客座编辑为 Marie-Louise Saboungi 博士和 Samuel D. Bader 博士。
