Label-Free Electrochemiluminescence Nano-aptasensor for the Ultrasensitive Detection of ApoA1 in Human Serum

Abstract

A molybdenum sulfide/zirconium oxide/Nafion (MoS2/ZrO2/Naf) based electrochemiluminescence (ECL) aptasensor for the selective and ultrasensitive detection of ApoA1 is proposed, with Ru(bpy)3 2+ as the luminophore. The chitosan (CS) modification on the nanocomposite layer allowed glutaraldehyde (GLUT) cross-linking, resulting in the immobilization of ApoA1 aptamers. Scanning electron microscopy, tunneling electron microscopy, and energy dispersive X-ray spectroscopy were used to characterize the nanocomposite, while electrochemiluminescence (ECL), cyclic voltammetry, and electrochemical impedance spectroscopy were used to analyze the aptasensor assembly. The nanocomposite was used as an electrode modifier, which increased the intensity of the ECL signal. Due to the anionic environment produced on the sensor surface following the specific interaction of the ApoA1 biomarker with the sensor, more Ru(bpy)3 2+ were able to be electrostatically attached to the aptamer-ApoA1 complex, resulting in enhanced ECL signal. The ECL aptasensor demonstrated outstanding sensitivity for ApoA1 under optimal experimental conditions, with a detection limit of 53 fg/mL and a wide linear dynamic range of 0.1–1000 pg/mL. The potential practical applicability of this aptasensor was validated by analyzing ApoA1 in human serum samples, with recovery rates of 94–108% (n = 3). The proposed assay was found to be substantially better compared to the commercially available enzyme-linked immunosorbent assay method, as reflected from over 1500 times improvement in the detection limit for ApoA1.

Electrochemical Nanoaptasensor Based on Graphitic Carbon Nitride/Zirconium Dioxide/Multiwalled Carbon Nanotubes for Matrix Metalloproteinase-9 in Human Serum and Saliva

“…17,18 Moreover, metal oxide nanoparticles (MNPs) known for their large surface area and catalytic capability have been reported to be employed in combination with other nanomaterials and have been found to elevate the performance of the biosensors. 19 Zirconium dioxide nanoparticles (ZrO 2 NPs) exhibit great potential in biosensing, 20,21 although research on their applications is relatively scarce compared to other metal oxide nanoparticles. Additionally, carbon nanomaterials possess several valuable traits, including specific surface area and electrical conductance.…”

“…In recent years, the integration of nanomaterials has gained significant attention in biosensing due to the exceptional advantages offered by the nanomaterials, including nanoscale dimensions, large surface area, high tunability, and adsorption capabilities. − Moreover, a substantial amount of research has focused on synergizing the properties of two or more nanomaterials along with an effective functionalization of the nanomaterial biorecognition element via covalent or noncovalent interactions. − Furthermore, this not only stabilizes the sensing interface but also facilitates easy read-out and enables enhanced recognition of analytes, particularly important for detecting disease biomarkers and pathogens. , Graphitic carbon nitride (g-C 3 N 4 ) has emerged as a promising two-dimensional (2D) semiconductor with tunable bandgap energy, facilitating efficient charge transfer for electrochemical biosensors. , To harness the physiochemical properties to their fullest, exfoliating bulk g-C 3 N 4 into nanosheets is a common strategy, which significantly increases the surface area for immobilization of biorecognition elements. , These g-C 3 N 4 nanosheets (g-C 3 N 4 -NS) have gained significant attention in various biosensing applications, such as photoelectrochemical, electrochemiluminescence, fluorescence, colorimetric, and electrochemical. , Moreover, metal oxide nanoparticles (MNPs) known for their large surface area and catalytic capability have been reported to be employed in combination with other nanomaterials and have been found to elevate the performance of the biosensors . Zirconium dioxide nanoparticles (ZrO 2 NPs) exhibit great potential in biosensing, , although research on their applications is relatively scarce compared to other metal oxide nanoparticles. Additionally, carbon nanomaterials possess several valuable traits, including specific surface area and electrical conductance .…”

Detection of Tetracycline with a CRISPR/Cas12a Aptasensor Using a Highly Efficient Fluorescent Polystyrene Microsphere Reporter System

“…Various nanoparticle probes, including semiconductor quantum dots, carbon nanotubes, superparamagnetic iron oxide nanoparticles, and metal nanoparticles (usually Au or Ag), have found applications in a wide range of health and food industries. − Furthermore, organic fluorescent nanoparticles, such as dye-loaded polymer nanoparticles, have emerged to be an appealing alternative …”