Exploring Selective Fluorescence Turn-On Sensing of Caspase‑3 with Molybdenum Disulfide Quenched Copper Nanoclusters: FRET Biosensor

• Published in: ACS applied materials & interfaces 2024-11, Vol.16 (45), p.61599-61608
• Main Authors: Indongo, Geneva, Madanan, Anju S., Varghese, Susan, Shkhair, Ali Ibrahim, Abraham, Merin K., Rajeevan, Greeshma, Kala, Arathy B., George, Sony
• Format: Article
• Language: English
• Subjects: Animals; apoptosis; Biological and Medical Applications of Materials and Interfaces; Biosensing Techniques - methods; biosensors; bovine serum albumin; cancer therapy; Caspase 3 - analysis; Caspase 3 - metabolism; caspase-3; Copper - chemistry; detection limit; Disulfides - chemistry; energy transfer; fluorescence; Fluorescence Resonance Energy Transfer; Humans; Metal Nanoparticles - chemistry; Molybdenum - chemistry; molybdenum disulfide; nanoparticles; nanosheets; patient care; Serum Albumin, Bovine - chemistry; ultraviolet radiation
• ISSN: 1944-8244; 1944-8252; 1944-8252
• DOI: 10.1021/acsami.4c10967

Sensing caspase-3 activity is essential for understanding the role of apoptosis in cancer dynamics, controlling therapeutic strategies, and improving patient care in cancer treatment. In this study, we demonstrate a highly sensitive recombinant human caspase-3 (rhC3) detection technique in biological fluids. This technique uses a copper nanocluster stabilized with bovine serum albumin (BSA-CuNCs) as a metal-based fluorescent biosensor, conjugated with anti-human caspase-3 (ahC3). To turn its fluorescence off, molybdenum disulfide nanosheets (MoS2 NSs) are added; this partnership is termed ahC3@BSA-CuNCs/MoS2 nanocouple. In the presence of rhC3, the energy transfer process is affected by strong ahC3/rhC3 interactions. When in close proximity, the rhC3 molecules cause detachment of the nanocluster from the MoS2 NS surface by attracting the ahC3 component of the nanocluster. This increases the distance between the nanocluster and quencher with a consequent restoration of intensity. As the concentration of rhC3 increases, the fluorescence intensity of the system also increases. A proportional response is seen in the concentration between 0.1 and 1.3 ng/mL with a very low limit of detection of 2.75 pg/mL and a quantification limit of 8.60 pg/mL. A simple filter paper strip was made to visually identify the presence of rhC3 under UV light.