Sensitivity enhancement of SPR assay of progesterone based on mixed self-assembled monolayers using nanogold particles

J Yuan, R Oliver, J Li, J Lee, M Aguilar, Y Wu
Biosensors & Bioelectronics 2007 August 30, 23 (1): 144-8
Commercially available nanoparticles have been employed as high mass labels for enhancing the binding signals and improving the detection sensitivity of surface plasmon resonance (SPR) assays. Such a signal enhancement is affected by the size and distance of the nanoparticles from the sensing surface. High signal amplifications are expected with increasing nanoparticle size and as the distance between the sensing surface and the nanoparticle is decreased. This paper describes a new way to improve the SPR assay sensitivity of small molecules using a mixed self-assembled monolayer (mSAM) surface to bring the nanogold particles close to the sensing surface. Progesterone (P4) was conjugated to ovalbumin (OVA) with an oligoethylene glycol (OEG) linker to form protein conjugate (P(4)-OEG-OVA), which was immobilized onto the mSAM surface. Inhibition immunoassays based on this mSAM/P4-OEG-OVA surface have demonstrated that 10nm nanogold dramatically improved the assay sensitivity of progesterone, lowering its limit of detection (LOD) from the original 372.7 to 4.9 ng L(-1). In addition, the high stability of the mSAM/P4-OEG-OVA surface was demonstrated by the use of a single chip for over 400 binding/regeneration cycles without any significant drop in antibody binding capacity and baseline shift.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"