Nanoparticle-based bio-bar codes for the ultrasensitive detection of proteins

Jwa Min Nam, C. Shad Thaxton, Chad A. Mirkin*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2163 Scopus citations

Abstract

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. Magnetic 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 bar codes can boost the sensitivity to 3 attomolar. Comparable clinically accepted conventional assays for detecting the same target have sensitivity limits of ∼3 picomdar, six orders of magnitude less sensitive than what is observed with this method.

Original languageEnglish (US)
Pages (from-to)1884-1886
Number of pages3
JournalScience
Volume301
Issue number5641
DOIs
StatePublished - Sep 26 2003

ASJC Scopus subject areas

  • General

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