New Reference – InnovaCoat® GOLD nanoparticles
December 6th, 2016
Vitamin B12 is a water-soluble vitamin, necessary for a variety of cellular functions such as DNA synthesis and normal blood formation. Low levels of vitamin B12 are mainly caused by low consumption of meat, fish and dairy products.
Commercially available kits for diagnostic applications are widely based on lateral flow assays. However, these kits have lower limits of detection in the tens of nmol/L range, which is far higher than the cut-offs for vitamin B12 insufficiency defined by a serum vitamin B12 level below 221 pmol/L.
The authors have developed a highly sensitive, innovative lateral flow assay system, capable of detecting serum vitamin B12 levels below the deficiency level of 221pmol/L. The lateral flow assay signal is amplified by a smartphone accessory and finally analyzed by a smartphone app. Altogether this constitutes the novel “NutriPhone” system.
The test uses a finger-stick of blood which is run on a lateral flow assay; this contains an innovative “spacer pad” whose function is to optimize the interaction between the sample B12 and the anti-vitamin B12 antibody. The strip is able to process whole blood samples, store the necessary reagents and has an in-built flow control.
The lateral flow signal is then amplified by the phone accessory (LEDs mounted on either side of a focussing lens) and the results analyzed by the smartphone platform, which is able to provide quantitative information from traditionally non-quantitative lateral flow strips.
Summary and Conclusion
The authors developed a competitive-type lateral flow assay in which the sample B12 is able to bind the AuNP-anti-B12 thanks to a novel spacer pad that enables a longer interaction between the two components. This particular strategy allows a more accurate detection of B12 when present in low concentrations. Signal amplification and data analysis by the NutriPhone app will provide quantitative data and the ability to track changes with time.
The validity of the system was proven in a human trial. However, more individuals need to be tested and a better usability still needs to be provided to generate a complete sample-in-answer-out test.
InnovaCoat® GOLD for the development of the “NutriPhone” lateral flow strip
This lateral flow assay utilizes a stable conjugate formed between a monoclonal anti-vitamin B12 IgG produced in mouse and 40nm gold nanoparticles. In this paper the authors relied on the 40nm InnovaCoat® GOLD conjugation kit. This kit offers several advantages:
InnovaCoat® GOLD – 40nm kit
- Quick and easy to use (30 seconds hands-on time)
- Uniform spherical shape and narrow size distribution
- Covalent bond, stable conjugates formed
- Excellent batch-to-batch reproducibility
- Easy transfer from R&D to manufacturing
All of the above benefits are key for developing a point-of-care (POC) assessment test for medical diagnostics.