Reduction of nonspecific protein binding on surface plasmon resonance biosensors.
Reduction of the nonspecific serum protein adsorption on a gold surface to levels low enough to allow the detection of biomarkers in complex media has been achieved using the N-hydroxysuccinimide (NHS) ester of 16-mercaptohexadecanoic acid. Carboxymethylated dextran (CM dextran), which is widely used, nonspecifically adsorbs enough proteins to mask the signal from target biomarkers in complex solutions such as serum or blood. The use of short-chain thiols greatly reduces the amount of nonspecific protein adsorption. Mixed layers of 11-mercaptoundecanoic acid or the NHS ester of 11-mercaptoundecanoic acid mixed layers with either 11-mercaptoundecanol or undecanethiol, and 16-mercaptohexadecanoic acid or the NHS ester of 16-mercaptohexadecanoic acid with hexadecanethiol, were also investigated for nonspecific protein binding properties as well as for biomarker signal response. The NHS ester of 16-mercaptohexadecanoic acid exhibits the largest signal for the biomarker myoglobin (including CM dextran) while offering a significantly diminished amount of nonspecific binding. The sensor has also been shown to detect interleukin-6 in cell culture media containing protein concentrations of at least 4 mg/mL.
Masson
Jean-Francois
JF
Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604, USA.
Battaglia
Tina M
TM
Cramer
Jeff
J
Beaudoin
Stephen
S
Sierks
Michael
M
Booksh
Karl S
KS
D000818:Animals; D001798:Blood Proteins / Q000032:analysis* / Q000378:metabolism; D002417:Cattle; D003470:Culture Media; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis* / Q000378:metabolism; D009211:Myoglobin / Q000032:analysis* / Q000378:metabolism; D011485:Protein Binding; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000379:methods*
D001798:Blood Proteins; D003470:Culture Media; D015850:Interleukin-6; D009211:Myoglobin