2020/03/26 by Jwa‐Min Nam, C. Shad Thaxton, Chad A. Mirkin
Biochemistry, Genetics and Molecular Biology · Engineering · #Advanced biosensing and bioanalysis techniques #Advanced Biosensing Techniques and Applications #Biosensors and Analytical Detection
paper · doi:10.1201/9781003056713-94
openalex publication_date 2020/03/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
An ultrasensitive method for detecting protein analytes has been developed. The system relies on magnetic microparticle probes with antibodies that specifically bind a target of interest [prostate-specific antigen (PSA) in this case] and nanoparticle probes that are encoded with DNA that is unique to the protein target of interest and antibodies that can sandwich the target captured by the microparticle probes. 1480Magnetic separation of the complexed probes and target followed by dehybridization of the oligonucleotides on the nanoparticle probe surface allows the determination of the presence of the target protein by identifying the oligonucleotide sequence released from the nanoparticle probe. Because the nanoparticle probe carries with it a large number of oligonucleotides per protein binding event, there is substantial amplification, and PSA can be detected at 30 attomolar concentration. Alternatively, a polymerase chain reaction on the oligonucleotide barcodes can boost the sensitivity to 3 attomolar. Comparable clinically accepted conventional assays for detecting the same target have sensitivity limits of ~3 picomolar, 6 orders of magnitude less sensitive than what is observed with this method.