Reliable and accurate creatinine analysis is critical for the timely diagnosis and treatment of individuals with renal disease. In a study published in the journal Biosensors and Bioelectronics, an innovative biosensor based on graphene nanoplatelet/polydopamine molecularly imprinted polymer is presented for trace-level creatinine detection in a variety of bodily fluids.
Study: A graphene nanoplatelet-polydopamine molecularly imprinted biosensor for Ultratrace creatinine detection. Image Credit: Shidlovski/Shutterstock.com
The Significance of Creatinine
Creatinine is a chemical found in blood and filtered out by the kidneys and then removed through the urine. Creatinine is a waste product created by the regular wear and tear of the body's muscles. Creatinine levels in a person's blood indicate their muscle mass as well as their renal function.
The removal of creatinine from the bloodstream via urine is largely determined by the glomerular filtering rate, and urinary creatinine removal is utilized in medical practice to monitor renal function.
Precise techniques for monitoring creatinine levels in bodily fluids are needed to diagnose and monitor individuals with renal diseases.
Creatinine Detection and Measurement
The Jaffe colorimetry technique, which uses picric acid to mix with creatinine and generate orange-red structures that can be identified and quantified, is the most popular technique for detecting creatinine in medical practice. However, this colorimetry technique may be affected by pigmented molecules such as bilirubin and certain medicines, which can make the results unreliable.
Several different techniques for detecting creatinine have been explored thus far, such as enzymatic catalysis and noble metal nanoparticle-based detection.
Creatinase is an enzyme that can detect creatinine with high sensitivity; however, the specimen's stability is compromised because of the enzyme's short activity duration.
The high cost of raw ingredients and poor specificity impede the clinical deployment of biosensors based on noble metal nanoparticles like gold and silver nanoparticles.
A robust and highly sensitive method for monitoring creatinine levels in bodily fluids is, therefore, clearly required.
The Role of Molecularly Imprinted Polymer Biosensors
Biosensors based on molecularly imprinted polymers (MIPs) for highly-sensitive detection of tiny molecules have seen recent developments.
Such biosensors mimic the natural interplay of antigens and antibodies by enabling monomers to catch sample molecules during the polymerizing phase and generate 3D imprinting areas that can detect the targeted molecules.
Unfortunately, these molecularly imprinted polymer biosensors have some drawbacks. These drawbacks include a time-consuming polymerizing procedure, weak polymeric conductivity, which causes inadequate sensitivity, and deeply buried template molecules, which results in large amounts of background noise and a limited detection range.
Advantages of Using Graphene Nanoplatelets
Graphene nanoplatelets (GNPs) are low-cost, high-conductivity nanoscale carbonaceous materials with high surface-to-volume ratios.
Considering the conducting network created by GNP, which allows for rapid electron transport, a GNP-based biosensor may exhibit exceptional sensitivity and a very low limit of detection (LOD).
What Did the Researchers Do?
A biosensor developed with a molecularly imprinted polydopamine layer on graphene nanoplatelets was presented in this work.
The unique approach of using surface-MIP avoids an excessively-thick MIP coating, allowing a greater number of template molecules to be located on or in close vicinity to the polymeric surface during the polymerizing procedure.
This guarantees that template molecules are completely removed, resulting in a larger range for detection.
Given appropriate conditions, dopamine hydrochloride (DA) monomers may self-polymerize and stick to different substrates, implying that the developed GNP/PDA-MIP composite may be manufactured in a facile one-pot approach, circumventing the laborious preparatory steps of traditional MIPs.
Important Findings of the Study
The team presented a unique MIP electrolytic biosensor based on graphene nanoplatelet and polydopamine composites for highly sensitive creatinine detection in different bodily fluids.
Using a simple and environmentally safe one-pot fabrication process, a coating of PDA was deposited onto the GNP surface.
The results of this study showed that this approach has good specificity and sensitivity, and dependable stability, because of the strong conductance of graphene nanoplatelets and the numerous imprinted areas of the surface-MIP.
Compared with existing creatinine biosensors, the most notable benefits of the proposed GNP/PDA-MIP biosensor were its incredibly broad linear response range and very low LOD.
This study presented an approach that allows for a potentially non-invasive point of care (POC) detection technique for the frontline medical diagnosis of creatinine levels and opens up the possibility for POC detection of various other biomarkers in bodily fluids for diagnosing a broad spectrum of illnesses.
Li, Y., Luo, L., Nie, M., Davenport, A., Li, Y., Li, B., & Choy, K.-L. (2022). A graphene nanoplatelet-polydopamine molecularly imprinted biosensor for Ultratrace creatinine detection. Biosensors and Bioelectronics. Available at: https://doi.org/10.1016/j.bios.2022.11463