Advancements in pretreatment-free portable sensing approaches for antibiotics detection in non-invasive livestock samples: Assessment and requirement of positive list system regulations

Synthetic antibiotics play an important role in livestock productivity and improve feed conversion rates by treating numerous animal-related diseases. The over-dosage of antibiotics to domestic animals has worsened antibiotic adulteration in food products, resulting in hazardous effects on humans and disturbing ecological and environmental systems. In this respect, establishing strict regulations and a positive list system (PLS), educating farmers, and fabricating simple, low-cost, rapid, non-invasive, pretreatment-free, and portable devices for precise, quick, and on-site recognition of antibiotics is undeniably essential and overdue. Such a device would adhere to the PLS guidelines, effectively detect maximum residue limits (MRLs), and protect both the environment and humans from the toxic effects of antibiotics. Here, we conduct a thorough review of the global status of PLS, its significance, and the latest advancements in research on on-site sensing strategies designed to detect antibiotics in livestock. Also, we address on-site sensing methods and analytical performances in detail and determine whether the limit of detection of described strategies meets MRL requirements. In addition, we describe future challenges, trends, perspectives, and analytical methods and provide an overview of sample extraction techniques. Current scientific and technological studies based on biomolecule and synthetic receptor-based sensors have considerably increased the ability to recognize antibiotics in livestock on-site. Colorimetric detection techniques offer the most potential for monitoring antibiotics in real time due to their straightforwardness, high selectivity, and sensitivity. This study highlights novel concepts, insights, and challenges associated with portable devices with potential use as simple paper-based sensors for detecting antibiotics in livestock.