The TEM image of the silver nanoparticle (40nm)-antibody
conjugates in 0.1M H₃BO₃, pH 6.5 + 0.1% BSA.
The white border 'halo' around the nanoparticles
are illustrative of the presence of antibody (the
lighter particles are the crystals of boric acid/BSA).

The unique chemical and physical properties of nanoparticles combined with high selectivity and specificity of antibodies make the antibody – nanoparticle conjugates extremely suitable and useful in many aspects of medical diagnostics and drug delivery.

With increasing developments in nanotechnology, metal nanoparticle – antibody conjugates are becoming more and more important in novel biological applications. With so many varied and widely used applications it is of great importance to produce conjugates of high quality and to find a way of monitoring and maintaining that quality.

At NPL we can optimise and thoroughly examine the immobilisation process in order to find the best methodology to produce stable, reproducible, biological active and sensitive conjugates. The parameters routinely investigated are:

• Antibody loading (antibody/nanoparticle ratio)
• Type of immobilisation buffer
• Molarity of the buffer
• pH of the buffer

Facilities are also available at NPL to monitor the quality of the synthesised antibody-metal conjugates. Techniques available include:

• Dynamic light scattering
• Transmission electron microscopy
• UV-Vis spectroscopy
• Fluorescence
• Electrochemical immunoassay and ELISA (for activity)

The conjugates developed at NPL have been successfully applied in lateral flow tests and in an electrochemical immunoassay for cardiac markers (myoglobin and troponin).

Contact

Customer Service tel: +44 20 8943 8637
E-mail: biodiagnostics_enquiries@npl.co.uk