Healthcare Technology Innovation Centre, Indian Institute of Technology, Madras, Chennai, Tamil Nadu 600113, India.
Department of Electrical Engineering, Indian Institute of Technology, Chennai, Tamil Nadu 600113, India.
Biosensors (Basel). 2021 Feb 14;11(2):49. doi: 10.3390/bios11020049.
This paper presents a lateral flow assay (LFA) for the quantitative, fluorescence-based detection of the cardiac biomarker troponin I (cTnI) that features an analytical strip made of cellulose filter paper. The results show that the wicking and test time are comparable to those obtained with conventional nitrocellulose (NC)-based LFAs. Further, the cellulose paper provides an excellent background with no auto-fluorescence that is very adequate in detecting fluorescent lines. While fluorescence that was generated with cellulose strips was lower when compared to that generated in NC strips, signals could be improved by layering carbon nanofibers (CNF) on the cellulose. A nonlinear behavior of the concentration-response relationship was observed for the LFA architectures with NC, cellulose, and cellulose-CNF in the 0 to 200 ng/mL cTnI concentration range. The measurements were consistent and characterized by coefficients of variation lower than 2.5%. Detection and quantitation limits that were in the range 1.28-1.40 ng/mL and 2.10-2.75 ng/mL were obtained for LFA with cellulose and cellulose CNF strips that are equivalent to the limits obtained with the standard NC LFA. Overall, we showed that commercially available filter paper can be used in the analytical strip of LFA.
本文提出了一种侧向流动分析（LFA）方法，用于基于荧光的心肌标志物肌钙蛋白 I（cTnI）的定量检测，其特点是采用纤维素滤纸条制成的分析条带。结果表明，吸液和测试时间与传统的硝酸纤维素（NC）基 LFA 相当。此外，纤维素纸提供了出色的背景，没有自发荧光，非常适合检测荧光线。虽然与 NC 条带相比，纤维素条带产生的荧光较低，但通过在纤维素上分层碳纳米纤维（CNF）可以提高信号。在 0 至 200 ng/mL cTnI 浓度范围内，NC、纤维素和纤维素-CNF 的 LFA 结构观察到浓度-响应关系的非线性行为。测量结果一致，变异系数低于 2.5%。对于纤维素和纤维素-CNF 条带的 LFA，检测限和定量限分别在 1.28-1.40 ng/mL 和 2.10-2.75 ng/mL 范围内，与标准 NC LFA 获得的限相同。总体而言，我们表明市售的滤纸条可用于 LFA 的分析条带。
