Femtomolar Detection of Lipopolysaccharide in Injectables and Serum Samples Using Aptamer-Coupled Reduced Graphene Oxide in a Continuous Injection-Electrostacking Biochip
| Autor: | Lihong Liu, Shuwen Liu, Yue Chen, Xiumei Hu, Junxin Niu, Jongyoon Han, Wei Ouyang |
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| Rok vydání: | 2018 |
| Předmět: |
Lipopolysaccharides
Analyte Staphylococcus aureus Aptamer DNA Single-Stranded Biosensing Techniques 010402 general chemistry medicine.disease_cause 01 natural sciences Pyrophosphate Analytical Chemistry chemistry.chemical_compound Mice Limit of Detection Phosphatidylcholine Lab-On-A-Chip Devices Candida albicans medicine Escherichia coli Animals Biochip Fluorescent Dyes Detection limit Chromatography Base Sequence 010401 analytical chemistry Water Aptamers Nucleotide Microfluidic Analytical Techniques Fluoresceins Fluorescence 0104 chemical sciences chemistry Graphite Adsorption |
| Zdroj: | Analytical chemistry. 91(3) |
| ISSN: | 1520-6882 |
| Popis: | A method for microfluidic sample preconcentration to detect femtomolar level of lipopolysaccharide (LPS) is introduced, enabled by 6-carboxyfluorescein (6-FAM) labeled aptamer-LPS binding along with reduced graphene oxide (rGO). The free FAM-aptamers can be adsorbed onto the surface of rGO, resulting in fluorescence quenching of background signals. Conversely, the aptamer-LPS complex cannot be adsorbed by rGO, so the fluorescence is maintained and detected. When an electric field is applied across the microchannel with Nafion membrane in the chip, only the fluorescence of aptamer-LPS complex can be detected and stacked by continuous injection-electrostacking (CI-ES). The method shows a high selectivity (in the presence of pyrophosphate, FAD+, NAD+, AMP, ADP, ATP, phosphatidylcholine, LTA, and β-d-glucans which respond positively to LAL) to LPS and an extreme sensitivity with the limit of detection (LOD) at 7.9 fM (7.9 × 10-4 EU/mL) and 8.3 fM (8.3 × 10-4 EU/mL) for water sample and serum sample, respectively. As a practical application, this method can detect LPS in injections and serum samples of human and sepsis model mouse and quickly distinguish Gram-negative bacteria Escherichia coli ( E. coli) from Gram-positive bacteria Staphylococcus aureus ( S. aureus) and fungus Candida albicans ( C. albicans). More importantly, by changing the aptamers based on different targets, we can detect different analytes. Therefore, aptamer-coupled rGO in a CI-ES biochip is a universal, sensitive, and specific method. For TOC only. |
| Databáze: | OpenAIRE |
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