An embedded microretroreflector-based microfluidic immunoassay platform.
Lab Chip
; 16(9): 1625-35, 2016 04 26.
Article
em En
| MEDLINE
| ID: mdl-27025227
ABSTRACT
We present a microfluidic immunoassay platform based on the use of linear microretroreflectors embedded in a transparent polymer layer as an optical sensing surface, and micron-sized magnetic particles as light-blocking labels. Retroreflectors return light directly to its source and are highly detectable using inexpensive optics. The analyte is immuno-magnetically pre-concentrated from a sample and then captured on an antibody-modified microfluidic substrate comprised of embedded microretroreflectors, thereby blocking reflected light. Fluidic force discrimination is used to increase specificity of the assay, following which a difference imaging algorithm that can see single 3 µm magnetic particles without optical calibration is used to detect and quantify signal intensity from each sub-array of retroreflectors. We demonstrate the utility of embedded microretroreflectors as a new sensing modality through a proof-of-concept immunoassay for a small, obligate intracellular bacterial pathogen, Rickettsia conorii, the causative agent of Mediterranean Spotted Fever. The combination of large sensing area, optimized surface chemistry and microfluidic protocols, automated image capture and analysis, and high sensitivity of the difference imaging results in a sensitive immunoassay with a limit of detection of roughly 4000 R. conorii per mL.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Imunoensaio
/
Rickettsia conorii
/
Dispositivos Lab-On-A-Chip
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Lab Chip
Assunto da revista:
BIOTECNOLOGIA
/
QUIMICA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos