Polish scientists use bacteriophage model to prove new colorimetric immunosensor concept

Gdansk, Poland: – Bacteriophage specialists Phage Consultants has participated in original research by scientists from two leading Polish universities that has developed a new method for detecting viruses, based on gold nanoparticles activated with the T7 bacteriophage.

The team has developed a colorimetric immunosensor that enables fast, simple, and selective detection of the T7 bacteriophage virus, chosen as a model organism for broad spectrum of viruses.

Their article ‘Antibody Modified Gold Nanoparticles for Fast and Selective Colorimetric T7 Bacteriophage Detection’ is published in the journal Bioconjugate Chemistry.

Visible aggregation

The immunosensor is based on gold nanoparticles (AuNPs) modified with covalently bonded anti-T7 antibodies. In use, T7 virions form immunological complexes with the antibody modified gold nanoparticles that causes them to aggregate.

This aggregation can be observed with the naked eye as a color change from red to purple, as well as with aUV−vis spectrophotometer. The researchers confirmed aggregate formation with SEM imaging while also demonstrating the sensor’s selectivity of T7 against the M13 bacteriophage. Measurement with a traditional plaque test showed detection limits as low as 1.08 x 1010plaque forming units (pfu) per milliliter of T7 in solution.

In contrast to biological tests, the colorimetric method allowed for detection of all T7 phages, not only those biologically active. This included phage ‘ghosts’ and fragments of virions.

Using similar antibodies available for a large variety of pathogenic viruses, the same concept can be flexibly adapted to detect many different human viruses.

Nanoscience and biotech specialists

The lead author, Dr. Adam Lesniewski, is senior research fellow at the Department of Electrode Processes at Warsaw’s Institute of Physical Chemistry, Polish Academy of Sciences (IPC PAS), specializing in nanotechnology, thin films and surface modification. The article is co-authored by the other six members of the research team, including two husband and wife pairings.

Dr. Marcin Los and Dr. Joanna M. Los are co-founders of Phage Consultants and experts in application of bacteriophage technologies to biotech research. Both are involved in research at University of Gdansk’s Department of Molecular Biology while Marcin was also an associate professor at IPC PAS.

Dr. Martin Jonsson-Niedziółka and his wife Dr. Joanna Niedziolka-Jonsson are also associated with the Institute, where Martin leads a group researching Charge Transfer Processes in Hydrodynamic Systems while Joanna specializes in surface modification and plasmon resonance, molecular recognition and bio inspired materials.

The remaining two authors, Anna Krajewska and Dr. Katarzyna Szot are both researchers at University of Gdansk’s Department of Molecular and Cellular Biology.

Fast and robust biosensing

“The modified gold nanoparticle model we describe in the article has several advantages over traditional methods of sensing viruses,” commented Dr. Marcin Los.

“For a start, it is much faster than a standard plaque test and classical immunoassays, being a one step method with no additional enzymatic or other amplification needed to read the result,” said Dr. Los.

“It is also more robust since this detection process does not use any bacteria−virus interactions,” he added.

The Phage Consultants team has also participated in related research at the two Polish Universities that has shown how biopolymer capped goldnanoparticles can form versatile probes for sensitive plasmonic viral biosensors.

About Phage Consultants

Bacteriophages (phages) are viruses that infect bacteria. First discovered around 1915, phages play an important role in viral biology, used to elucidate DNA viral reproduction through lytic and lysogenic cycles. They have been used for almost a century as alternatives to antibiotics and can have therapeutic effect against multi-drug-resistant strains of many bacteria.

Based in Poland, Phage Consultants is a contract research and manufacturing organization that specializes in bacteriophage characterization, production, infection and contamination control and assisting companies whose production is based on microbial activities in preventing phage, bacterial, fungal and viral contaminations.

Phage Consultants are specialists in the field of bacteriophage biology with specific expertise on phage activity in bioprocessing. Its team provides unique assistance to pharmaceutical and biotech companies, offering a range of services from personal training to consulting and process optimization in phage growth limitation. The company also advises and assists clients in the development of new production facilities.

Resources

Click on Bioconjugate Chemistry for link to the original posted article (paywall protected).