Metal nanoparticles based electrochemical biosensing of neutrophil gelatinase-associated lipocalin biomarker for monitoring acute kidney injury

Abstract

Neutrophil gelatinase-associated lipocalin (NGAL), commonly known as Lipocalin-2 (LCN2), is a protein that is secreted by neutrophils and damaged renal tubular epithelial cells. This 25-kDa secretory protein with 178 amino acids can be detected in both urine and plasma samples. NGAL serves as a marker for kidney injury, and its release is triggered exclusively when the kidneys experience stress due to inflammation and infection. Urinary NGAL is generated within the renal tubules, exactly in the thick ascending limb of Henle and the collecting-ducts. The conventional analytical approaches for the detection of NGAL urinary markers display some key limitations, including being expensive, time-consuming, often inaccurate, and practically difficult to apply for the analysis. Interestingly, the development of nanomaterials in biology and medicine has provided an ideal solution to the early diagnosis and treatment of acute kidney injury (AKI). Thus, in this review, we emphasize the development of electrochemical biosensors for NGAL detection, which covers the principle, key design, and biosensor strategies using functionalized nanomaterial-based (carbon nanostructures, metal nanoclusters, metal nanoparticles, metal-organic frameworks, and quantum dots) electroanalytical detection methods. The analytical outcomes of these electrochemical biosensors are also compared and summarized with relevant clinical samples. This promising discipline, at the interface of nanomaterials and biosciences, provides wide prospects for interdisciplinary researchers that comprise nanomaterial preparation, biological functionalization, biosensor platforms, and targeted theranostics in biomedical diagnostics. The potential strategies for new electrode design, important biosensing characteristics, key challenges, and future opportunities toward NGAL determination are also described.