Sample-to-Answer Robotic ELISA

Abstract

Enzyme-linked immunosorbent assays (ELISA), as one of the most used immunoassays, have been conducted ubiquitously in hospitals, research laboratories, etc. However, the conventional ELISA procedure is usually laborious, occupies bulky instruments, consumes lengthy operation time, and relies considerably on the skills of technicians, and such limitations call for innovations to develop a fully automated ELISA platform. In this paper, we have presented a system incorporating a roboticmicrofluidic interface (RoMI) and a modular hybrid microfluidic chip that embeds a highly sensitive nanofibrous membrane, referred to as the Robotic ELISA, to achieve human-free sampleto-answer ELISA tests in a fully programmable and automated manner. It carries out multiple bioanalytical procedures to replace the manual steps involved in classic ELISA operations, including the pneumatically driven high-precision pipetting, efficient mixing and enrichment enabled by back-and-forth flows, washing, and integrated machine vision for colorimetric readout. The Robotic ELISA platform has achieved a low limit of detection of 0.1 ng/mL in the detection of a low sample volume (15 μL) of chloramphenicol within 20 min without human intervention, which is significantly faster than that of the conventional ELISA procedure. Benefiting from its modular design and automated operations, the Robotic ELISA platform has great potential to be deployed for a broad range of detections in various resource-limited settings or high-risk environments, where human involvement needs to be minimized while the testing timeliness, consistency, and sensitivity are all desired.

Recent Advances in CRISPR/Cas-Based Biosensors for Protein Detection

“…Antibodies are routinely used as biological recognition elements for proteins in immunosensors, which are currently the most important and widely used biosensors for protein detection [ 54 ]. The traditional ELISA method is well-recognized as the gold standard for protein detection [ 55 ], and its detection principle is based on the formation of a sandwich antibody–antigen–antibody structure, in which the enzyme (usually horseradish peroxidase (HRP)) labeled on the antibody induces the enzymatic signal amplification for measuring the concentration of targets. However, it is still not sensitive enough for the rapid detection of ultralow concentrations of protein biomarkers [ 56 , 57 ].…”

Artificial Intelligence-Controlled Microfluidic Device for Fluid Automation and Bubble Removal of Immunoassay Operated by a Smartphone

“…The developed AI app successfully recognized various fluidic states in the reaction chamber and appropriately actuated the microfluidic device for performing ELISA by resolving fluid errors such as bubbles and incomplete filling in the reaction space. Compared to the manually controlled microfluidic immunoassay that already offers improved results than the conventional ELISA, the AI-powered automated microfluidic platform provided better repeatability by reducing the overlapping of the test results with the other concentrations result due to high standard deviation, which is significantly influential to the assay outcomes and contributing to the lower limit of detection (LOD) for diagnosing cTnI. ,− Thus, the clinical application of this proposed device may have a great impact for replacing the manual method by AI for clinical applications and commercialization, also saving lives by diagnosing cardiac diseases in a very early stage.…”

An Electromechanical Lab-on-a-Chip Platform for Colorimetric Detection of Serum Creatinine

“… 32 Moreover, a robotic system was used to perform automated ELISA protocols for chloramphenicol detection using colorimetric measurements. 33 Protocols were conducted on a microfluidic chip, where pneumatically driven loading, mixing, and washing steps were achieved with a robotic arm. A fully automated microfluidic platform was also developed for CD4 cell counting with colorimetric ELISA protocols.…”

“…For instance, automatic water analysis was achieved with a 3D-printed robotic system coupled with a syringe pump to transfer samples and reagents, temperature and conductivity sensors to provide accurate measurement, and a webcam for colorimetric pH analysis on a 96-well plate . Moreover, a robotic system was used to perform automated ELISA protocols for chloramphenicol detection using colorimetric measurements . Protocols were conducted on a microfluidic chip, where pneumatically driven loading, mixing, and washing steps were achieved with a robotic arm.…”