Nanobioconjugates for Signal Amplification in Electrochemical Biosensing

Abstract

Nanobioconjugates are hybrid materials that result from the coalescence of biomolecules and nanomaterials. They have emerged as a strategy to amplify the signal response in the biosensor field with the potential to enhance the sensitivity and detection limits of analytical assays. This critical review collects a myriad of strategies for the development of nanobioconjugates based on the conjugation of proteins, antibodies, carbohydrates, and DNA/RNA with noble metals, quantum dots, carbon- and magnetic-based nanomaterials, polymers, and complexes. It first discusses nanobioconjugates assembly and characterization to focus on the strategies to amplify a biorecognition event in biosensing, including molecular-, enzymatic-, and electroactive complex-based approaches. It provides some examples, current challenges, and future perspectives of nanobioconjugates for the amplification of signals in electrochemical biosensing.

Changing Cross-Reactivity for Different Immunoassays Using the Same Antibodies: Theoretical Description and Experimental Confirmation

“…A possible variant of such an enhanced label consists in the formation of oligomeric complexes from several initial labels by their chemical conjugation or affine aggregation during the work of the sensor. (See recent reviews [62][63][64][65] with descriptions of such amplifying techniques.) (2) If it is necessary to expand the selectivity of the immunosensor, i.e., to increase the CR for structurally similar compounds recognized by the used antibodies, the opposite actions are required-an increase in the concentrations of antibodies and modified competing antigens and their use in a non-equimolar ratio.…”

Carbon Nanomaterials (CNMs) and Enzymes: From Nanozymes to CNM-Enzyme Conjugates and Biodegradation

“…However, the occurrence of direct electron transfer (DET) is a matter of ongoing debate, depending on the type of enzymes under consideration, the accessibility of their redox-active site to the CNMs, and the type of direct or indirect contact between CNMs and enzymes [ 265 ]. The electronic properties of CNMs render them attractive building blocks for electrochemical biosensors, besides the more traditional optical alternatives [ 366 , 367 ].…”

Hybrid Nanobioengineered Nanomaterial-Based Electrochemical Biosensors

“…Biosensor technology based on nanobiohybrid materials represents a vast field that significantly impacts healthcare, the environment, and food quality control. These functional platforms promote target molecule detection with high specificity and sensitivity, particularly in the biomedical field [1,33,50,93,117,178]. Furthermore, the rational design of the nanobiohybrids has been demonstrated to enhance the response and long-term stability of the resultant devices due to the incorporation of nanomaterials with improved properties that promote a favorable nanoenvironment for bioreceptors anchoring.…”

“…Nanobioengineered platform-based electrochemical biosensors have been implemented in biomedicine, environmental, food, and security industries, demonstrating their versatility and great potential. Notably, in the biomedical field, modern nanobioengineered biosensing devices are escalating their horizon to face multitudinous medical complications, i.e., providing early, accurate, and specific diagnoses of diseases [1][2][3].…”