Aptamers against Pathogenic Bacteria: Selection Strategies and Apta-assay/Aptasensor Application for Food Safety

Abstract

Pathogenic bacteria are primarily kinds of detrimental agents that cause mankind illness via contaminated food with traits of multiple types, universality, and low content. In view of the detection demands for rapidity, aptamer recognition factors emerged as a substitution for antibodies, which are short single strands of nucleic acid selected via in vitro. They display certain superiorities over antibodies, such as preferable stability, liable modification, and cost-efficiency. Taking advantage of the situation, numerous aptamers against pathogenic bacteria have been successfully selected and applied, yet there are still restrictions on commercial availability. In this review, the strategies/approaches to key sections in pathogen aptamers SELEX and post-SELEX are summarized and sorted out. Recently, optical, electrochemical, and piezoelectric aptamer-based assays or sensors dedicated to pathogen detection have been critically reviewed. Ultimately, the existing challenges and future trends in this field are proposed to further promote development prospects.

Current Scenario of Pathogen Detection Techniques in Agro-Food Sector

“…The integration of aptamer-based assays with microfluidics, lateral flow, and surface-fabrication techniques can offer multiplexing However, the applicability of aptamer-based immunoassays is not as wide as antibodies due to complexity in the selection of highly-specific aptamers [102]. The production of target-specific aptamers via the systematic evolution of ligands by exponential enrichment (SELEX) and post-SELEX is a time-consuming process [103]. In the development of specific aptamers, microbial pathogens and their structural/non-structural proteins and enzymes are the targets.…”

Dual-Target Electrochemical Sensor Based on 3D MoS2-rGO and Aptamer Functionalized Probes for Simultaneous Detection of Mycotoxins

“…In comparison, electrochemical sensors with rapid response and simple operation as one of the promising alternatives due to its high sensitivity and portability, have drew a lot of attention of environmental pollution and food safety fields ( Wang et al, 2019 ). Aptamer as a new recognition element was obtained from the “Systematic Evolution of Ligands by Exponential Enrichment (SELEX).” Compared with traditional antibody, aptamer possess many competitive advantages for sensing applications, including excellent stability during long-term storage, low-cost chemical synthesis, versatility in modification, low toxicity and lack of immunogenicity ( Li et al, 2021 ) ( Liu et al, 2022 ). Up to now, many specific aptamers combined with surface enhanced raman ecattering (SERS) ( Li et al, 2017 ), fluorescence ( Yang et al, 2017 ), colorimetric ( Setlem et al, 2020 ), surface plasmon resonance (SPR) ( Mahmoudpour et al, 2019 ), chemiluminescent (ECL) ( Yao et al, 2019 ) and electrochemical ( Qian et al, 2020 ) techniques have been well developed in the detection of mycotoxins.…”

Isolation of Bacteria Aptamers with Non-SELEX for the Development of a Highly Sensitive Colorimetric Assay Based on Dual Signal Amplification

“…In the construction of bioassays/biosensors, recognition elements play a significant role in signal transduction. Wherein, aptamers, as a class of nucleotide sequences isolated in vitro , are extensively employed owing to their preponderance of small size, variable structure, and nontoxicity . Aiming at bacterial-type targets of aptamers, cell-SELEX is commonly executed because it does not require knowledge of target cell surface proteins or purified target molecules, but the time-consuming implementation of multiple cycles of selection is an unavoidable disadvantage .…”

“…19 Aiming at bacterialtype targets of aptamers, cell-SELEX is commonly executed because it does not require knowledge of target cell surface proteins or purified target molecules, but the time-consuming implementation of multiple cycles of selection is an unavoidable disadvantage. 19 In this case, Kim et al 20,21 proposed non-SELEX to further promote the selection development of bacterial target aptamers with high efficiency. This method removed unbound DNA from the pool through repeated centrifugation-based partitioning, omitting the reduplicative combination of incubation, separation, and amplification necessary for SELEX.…”

“…Wherein, aptamers, as a class of nucleotide sequences isolated in vitro , are extensively employed owing to their preponderance of small size, variable structure, and nontoxicity . Aiming at bacterial-type targets of aptamers, cell-SELEX is commonly executed because it does not require knowledge of target cell surface proteins or purified target molecules, but the time-consuming implementation of multiple cycles of selection is an unavoidable disadvantage . In this case, Kim et al , proposed non-SELEX to further promote the selection development of bacterial target aptamers with high efficiency.…”