GHK-Cu Peptide Mimics Laccase Enzyme for Cost-Effective Phenolic Compound Detection
Background
Natural laccase enzymes are vital for detecting and degrading various phenolic compounds, which are prevalent environmental pollutants and important biomarkers. However, their widespread use is significantly hampered by high production costs and inherent instability under diverse conditions. This study investigated whether the well-known copper peptide GHK-Cu could exhibit stable laccase-like catalytic activity to overcome these limitations.
Study Design
Results
The GHK-Cu peptide demonstrated remarkable laccase-like activity, exhibiting a maximum reaction rate (Vmax) of 1.735 × 10-4 mM·s-1 and a Michaelis constant (Km) of 0.061 mM, which indicates strong substrate affinity and excellent catalytic efficiency. The developed colorimetric sensor showed robust performance for epinephrine (EP), with a linear response range spanning 20-240 μM and a low limit of detection (LOD) of 9.5 μM. For 2-aminophenol (2-AP), the sensor achieved linear response ranges of 14-100 μM in ultrapure water (LOD 2.56 μM) and 2-120 μM in seawater (LOD 1.65 μM), showcasing its versatility across different matrices. > The smartphone-integrated cotton-based sensor for 2-AP in seawater further extended detection capabilities, providing linear response ranges of 0-0.2 mM and 0.2-1 mM, with an impressive LOD of 0.033 mM, enabling highly portable and rapid analysis.
Why It Matters
This research unveils GHK-Cu's significant potential as a stable, cost-effective, and readily available alternative to natural laccase enzymes, paving the way for new biomimetic enzyme designs. The successful development of a robust colorimetric detection method and a portable, smartphone-integrated sensor could revolutionize on-site environmental monitoring for phenolic contaminants and potentially lead to new diagnostic tools. Future research should focus on expanding the sensor's applicability to a wider range of phenolic compounds and validating its performance in more complex real-world samples, moving towards commercial deployment.