Copper Peptide GHK-Cu Shows Promise as Enzyme Mimic for Detecting Toxic Compounds

Environmental monitoring just got a boost from an unexpected source: a copper peptide already familiar to the cosmetics industry. Researchers at Chongqing University discovered that GHK-Cu (glycyl-L-histidyl-L-lysine copper), commonly used in anti-aging skincare products, possesses remarkable laccase-like enzymatic activity that can detect harmful phenolic compounds in water.

Phenolic compounds pose significant environmental and health risks, contaminating water bodies through industrial discharge from pharmaceutical, dye, and pesticide manufacturing. Traditional detection methods require expensive equipment and complex procedures, limiting their use for routine monitoring.

The research team demonstrated that GHK-Cu can catalyze the oxidation of phenolic compounds through a copper redox cycle, showing impressive kinetic parameters with a Vmax of 1.735 × 10⁻⁴ mM·s⁻¹ and Km of 0.061 mM. They successfully developed colorimetric sensors that detected epinephrine (20-240 μM range) and 2-aminophenol (2-120 μM range) with high sensitivity. Most notably, they created a smartphone-integrated cotton-based sensor for field detection of 2-aminophenol in seawater.

This discovery offers several advantages over natural laccase enzymes: GHK-Cu is commercially available, more stable, and significantly less expensive. The peptide's safety profile, already established through cosmetic use, makes it particularly attractive for environmental applications. The portable sensor design could revolutionize water quality monitoring, especially in remote locations where laboratory analysis isn't feasible.

While promising, the technology requires validation across broader environmental conditions and longer-term stability testing before widespread deployment.