Single-molecule fluorescence methods for protein biomarker analysis

A generalised protein identification method for novel and diverse sequencing technologies

“…We also studied the performance when a reduced set of identifiable AAs is used. This simulates situations such as where some AAs are fluorescent-labelled so that they are identified through the reduction of intensity after each Edman cycle, whereas the unlabeled AAs do not cause a reduction [16, 48]. Previous studies have utilised such techniques to generate protein fingerprints [19, 20, 13], although none of them proposed a general method for identifying the originating protein from a large database.…”

“…Any sequencing method is prone to errors. For devices based on fluorescence techniques, these errors might arise due to inefficient labelling and detection [16, 48]. For devices dependent upon the translocation of a protein, errors may arise due to the non-uniform speed of the sequence and possibly during the decoding of the signals.…”

Ultrasensitive fluorescence immunoassay of pepsinogen I based on enzyme-triggered decomposition of AuNCs/MnO2

“…Therefore, uorescent signals have a high signal-to-noise ratio, and weak signals can be easily detected, realizing the purpose of highly sensitive detection. [19][20][21] However, there are still two key scientic challenges in the pursuit of developing low-cost, sensitive, and simple uorescence immunoassay strategies. In general, many uorescent substrates are synthesized either as complex pathway organic molecules or as inorganic materials under harsh reaction conditions (high temperature, hydrothermal) with toxic raw materials.…”

Single-Molecule Protein Analysis by Centrifugal Droplet Immuno-PCR with Magnetic Nanoparticles

“…Recently, ultrasensitive immunoassays have shown rapid progress, such as single molecular methods and electrochemiluminescence. − Among them, the single-molecule immunoassay has drawn increasing attention. − Single-molecule analysis refers to an emerging form of measurement technique which is capable of detecting many single molecules simultaneously and/or processing larger and more complex samples. − In principle, it relies on the random partitioning of target proteins into a large number of microwells or microdroplets for single-molecule profiling, showing applications for a wide range of biomarkers. − A main challenge of the single-molecule immunoassay is the use of microchip-based platforms, which can cause two problems. Sample partitioning is key to the single-molecule assay; several methods of microdroplet generation have been reported, such as T-junction-type microfluidic chips, droplet oscillation, and microbead arrays. − The second is the use of microfluidic pumps which are difficult to access in clinal environments. − …”