Department of Chemical Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
ACS Appl Mater Interfaces. 2014 Mar 12;6(5):3394-405. doi: 10.1021/am405461j. Epub 2014 Feb 28.
Carbon-based sensors for wide-range electrochemical detection of redox-active chemical and biological molecules were fabricated by the electrospinning of polyacrylonitrile fibers directly onto a polyacrylonitrile-coated substrate followed by carbonization at 1200 °C. The resulting electrospun carbon nanofibers (ECNFs) were firmly attached to the substrate with good mesh integrity and had high densities of electronic states (DOS), which was achieved without need for further modifications or the use of any additives. The mass of ECNFs deposited, and thus the electroactive surface area (ESA) of the sensor, was adjusted by varying the electrospinning deposition time, thereby enabling the systematic manipulation of the dynamic range of the sensor. A standard redox probe (Fe(CN)6(3-/4-)) was used to demonstrate that the ECNF sensor exhibits strong electrocatalytic activity without current saturation at high analyte concentrations. Dopamine was used as a model analyte to evaluate the sensor performance; we find that the ECNF device exhibits a dynamic range ∼10(5) greater than that of many existing carbon-based sensors. The ECNF sensors exhibited excellent sensitivity, selectivity, stability, and reproducibility for dopamine detection.
通过将聚丙烯腈纤维直接纺丝到涂有聚丙烯腈的基底上，然后在 1200°C 碳化，制备了用于电化学检测氧化还原活性化学和生物分子的宽范围碳基传感器。所得的静电纺丝碳纳米纤维（ECNFs）与基底牢固地附着在一起，具有良好的网格完整性和高密度的电子态（DOS），而无需进一步修饰或使用任何添加剂。通过改变静电纺丝沉积时间来调整 ECNFs 的沉积量，从而调整传感器的电活性表面积（ESA），从而可以系统地操纵传感器的动态范围。使用标准氧化还原探针（Fe（CN）6（3-/4-））证明 ECNF 传感器在高分析物浓度下没有电流饱和时表现出很强的电催化活性。多巴胺被用作模型分析物来评估传感器性能；我们发现，ECNF 器件的动态范围比许多现有的碳基传感器大 10^5 倍。ECNF 传感器对多巴胺检测表现出优异的灵敏度、选择性、稳定性和重现性。
