Technology Features & Specifications
Molecularly imprinted polymers (MIP) have proven to be robust and stable to identify and measure analytes – the chemical constituents of substances. In particular, MIP ﬁlms that are used to detect certain compounds via a quartz crystal microbalance (QCM) transducer stand out among MIP sensors, as they offer attractive performance, such as high speciﬁcity, low cost, ease of use and rapidness of detection.
There are two approaches to combine MIPs with QCM crystal: one is to immobilise a ready-made MIP on a transducer using physical entrapment or chemical coupling. The other is to in situ assemble an MIP layer directly on the transducer surface. However, the challenge so far has been to find a simple and general protocol to immobilise MIP ﬁlm on the QCM crystal.
This approach uses a simpler, inexpensive and faster method to generate MIP ﬁlm on the QCM crystals using mussel-inspired polymer. The polymerisation or inking of dopamine molecules in the presence of the template molecule (1,3,5-pentanetricarboxylic acid) can produce an adherent molecularly imprinted polydopamine ﬁlm coating on QCM crystals. This method offers high hydrophilicity, high biocompatibility and controllable thickness, which makes this molecularly imprinted polydopamine ﬁlm an attractive recognition element for sensors.
This sensor technology comprises: one or multiple piezoelectric quartz chips, one or multiple flow cells to hold the quartz chips, and an electronic system. Each quartz chip is coated with a thin layer of proprietary molecularly imprinted material, which has complementary molecular cavities that are the same size, shape and interactions as the template and analyte molecules.
After connecting the flow cell with the electronic system, voltage is applied onto the quartz chip to generate a frequency signal based on the piezoelectric effect, which is then recorded by the acquisition software. When samples containing target analyte molecules are introduced, the target molecules will selectively re-bind to the imprinted cavities on the quartz chip causing mass changes, which changes its frequency signal and energy dissipation. The frequency changes can then be quantitatively correlated to the analyte concentration due to the molecules absorption, and molecular interactions on the sensor imprinted surface.
The molecularly imprinted piezoelectric quartz sensor can be used in the areas of chemical, biological and medicinal, agriculture, and materials analysis. Some potential applications for research, testing and monitoring include:
- Medical: Cholesterol, blood glucose, blood gas analyser, pregnancy testing, drug delivery (inhibitors), and infectious disease
- Bioreactor: Nucleic acid hybridisation, enzymes, protein-protein interaction, protein-sugar and protein-RNA, and mismatched base pair
- Home healthcare diagnostics: Blood glucose, cholesterol, pregnancy test, HIV test, colon cancer screening, and urinary tract infection test
- Point of Care (PoC) testing: Urine test, blood glucose, blood gas and electrolytes, rapid coagulation test, and rapid cardiac markers
- Security and bio-defence: Chemical threat agents & simulants monitoring, and biological threat agents & simulants monitoring
- Agriculture: Bacteria, fungus, pesticides, herbicides, feed additives, nitrates, and phosphates and fertilizers
- Food industry: Bacteria and virus tests, food adulterates analysis, food nutrients, cholesterol, and vitamins
- Food toxicity: Food poisoning, mycotoxins, neurotoxins, dinotoxin, myotoxin, cyanotoxin, exotoxins, endotoxins
- Environment: Polycyclic aromatic hydrocarbons (PAHs), pesticides, phthalic acid esters, polychlorinated biphenyls, and gas emissions
- Research laboratories: New materials evaluation, nanotubes, nanoparticles, quantum dots, graphene, graphene oxide, battery, catalyst, and cleaner
The benefits include the following:
- Real-time and label-free sensing of mass changes and energy dissipation on a surface originated from molecules adsorption, and molecular interactions
- Monitor multiple targets simultaneously
- High sensitivity
- Excellent selectivity
- High modularity
- Low maintenance and low cost