Researchers have proposed an innovative electroanalytical method for determining creatinine levels in urine, leveraging eco-friendly biochar derived from sugarcane bagasse. This development is particularly noteworthy as it provides a sustainable alternative to traditional enzymatic methods, which are often limited by their need for strict environmental controls.

Creatinine, a byproduct of muscle metabolism excreted through the kidneys, serves as a vital biomarker for kidney function. Traditional detection methods, such as the Jaffé reaction, while widely used, suffer from interference by various substances present in urine samples, which can skew results. In contrast, the new method utilizes a biochar-modified carbon paste electrode that spontaneously interacts with copper ions to form creatinine-copper complexes. This interaction effectively suppresses the copper voltammetric signal, providing a reliable measure of creatinine concentration.

The method exhibited a linear dynamic range of 300-700 µmol L−1 and was able to accurately determine creatinine in synthetic urine samples. Notably, the detection and quantification limits were set at 91.0 µmol L−1 and 300 µmol L−1, respectively. The method also demonstrated high selectivity against common metallic species found in urine and was effective even in the presence of equimolar concentrations of uric acid.

Further emphasizing its practical application, the method achieved creatinine recovery rates of 101±7% at the quantification limit and 100±7% at typical urine creatinine concentrations post-dilution. This indicates not only the method’s accuracy but also its robustness and reliability in a synthetic urine matrix.

By utilizing biochar, an environmentally beneficial material produced from agricultural waste, this method also aligns with Sustainable Development Goals by promoting sustainable production practices and contributing to environmental conservation. This innovative approach, therefore, not only enhances the accuracy of biomarker analysis in clinical diagnostics but also supports sustainable practices in scientific research.