Scientists are turning to automation and robotics to speed up one of the most difficult challenges in modern medicine: discovering new antibiotics capable of fighting dangerous bacterial infections.

Researchers at the University of York have developed a robot-assisted chemical system that can rapidly create and test large numbers of potential antimicrobial compounds. The approach produced a library of 1,440 new iridium-based chemical complexes, allowing researchers to examine a much larger chemical space than would normally be practical through conventional laboratory methods.

A New Role for Laboratory Robots

Traditional drug discovery can be slow because scientists often need to prepare compounds individually before testing them against bacteria.

The new approach changes that process by combining chemical synthesis, automation and biological screening.

An automated liquid-handling robot was used to carry out a one-pot, three-component chemical reaction. This allowed researchers to produce a large collection of related iridium(III) compounds and then evaluate their biological activity.

The system generated 1,440 different complexes, creating a broad collection of candidates for further investigation.

Searching for New Antibacterial Chemistry

The research focused on metal-containing compounds known as iridium(III) complexes.

Scientists are interested in these molecules because metal-based chemistry can provide mechanisms that differ from those of many conventional antibiotics.

After the robotic synthesis process, the researchers screened the compounds directly from the reaction mixtures rather than requiring every compound to undergo a lengthy purification process before testing.

This direct-to-biology strategy can reduce the time and resources needed to evaluate large chemical libraries.

Promising Activity Against Bacteria

The screening identified several compounds that showed antibacterial activity against Staphylococcus aureus, a bacterium capable of causing a range of infections.

One leading compound demonstrated activity at low-micromolar concentrations against several Gram-positive bacterial pathogens.

Researchers also examined its effects on red blood cells and mammalian cells as part of an early assessment of biological selectivity.

The leading candidate showed relatively low haemolytic activity, while additional testing indicated moderate cytotoxicity. These results do not mean the compound is ready to become a medicine, but they provide a starting point for further drug-development research.

How the Candidate May Work

Further experiments suggested that the leading compound interacts with bacterial membranes.

Researchers observed mild membrane depolarisation along with changes in the appearance of bacterial nucleoids.

A membrane-associated mechanism is significant because compounds that attack bacteria through physical or structural processes can potentially offer different pathways for overcoming resistance compared with traditional antibiotics.

However, laboratory activity against bacteria is only an early stage of drug discovery. Considerable research is required before determining whether such compounds could become safe and effective treatments in humans.

Why Automation Matters

Antibiotic discovery faces a major efficiency problem.

Scientists can design enormous numbers of theoretically interesting molecules, but testing each one individually can require substantial amounts of time, laboratory space and funding.

Robotic systems can perform repetitive chemical and biological procedures rapidly and consistently.

Instead of researchers manually preparing each reaction, automated equipment can handle many reactions in parallel.

This makes it possible to explore chemical combinations that might otherwise be ignored simply because they are too numerous to investigate using conventional methods.

The Growing Antibiotic Resistance Challenge

The research arrives as antibiotic resistance continues to create pressure for new treatments.

Bacteria can develop resistance through genetic changes and other biological mechanisms, reducing the effectiveness of existing medicines.

Scientists therefore need not only more antibiotics but also compounds that operate through new biological mechanisms.

Other research groups are pursuing different technology-based approaches. For example, researchers have recently used high-throughput screening to search for compounds that interfere with bacterial DNA gyrase, identifying a previously unrecognized molecule called Pyr-AMC as a possible starting point for future antibiotic development.

Artificial intelligence is also being explored in antibiotic research. Stanford researchers, for instance, have developed an AI-assisted approach for identifying antimicrobial polymers inspired by bacteria-killing peptides.

From Thousands of Molecules to a Few Candidates

A major advantage of high-throughput research is that it allows scientists to start with a very large pool of chemical possibilities.

But producing thousands of molecules does not mean thousands will become medicines.

Most candidates will eventually be eliminated because of insufficient antibacterial activity, toxicity, instability, poor selectivity or other limitations.

The purpose of the robotic platform is therefore not to produce an instant antibiotic, but to dramatically accelerate the early stage of discovery and help researchers identify promising candidates for deeper investigation.

A New Model for Drug Discovery

The University of York work demonstrates how chemistry laboratories are increasingly becoming automated research environments.

Robotic systems can perform repetitive experiments while scientists focus on designing experiments, interpreting results and understanding biological mechanisms.

The combination of automated synthesis and direct biological screening could eventually be applied beyond antibiotics.

Similar approaches may help researchers investigate compounds for other infectious diseases and potentially other areas of drug discovery.

What Comes Next

The promising compounds identified in the study will require additional investigation to determine their detailed mechanisms, safety characteristics and effectiveness in more complex biological systems.

Researchers will need to establish whether the antibacterial activity observed in laboratory testing can translate into useful therapeutic effects while maintaining an acceptable safety profile.

Further optimization could also modify the chemical structures to improve their effectiveness and reduce unwanted biological effects.

The long-term goal is to transform promising chemical leads into candidates suitable for more advanced preclinical research.

Automation Could Change the Pace of Antibiotic Discovery

The development of a robotic system capable of creating and screening 1,440 new iridium complexes demonstrates how automation can expand the boundaries of chemical research.

Instead of searching through potential antibiotics one compound at a time, scientists can increasingly use robots and automated workflows to explore thousands of possibilities systematically.

The approach does not guarantee a new antibiotic, but it provides researchers with a faster way to search for molecules that conventional methods might take much longer to discover.

As antibiotic resistance continues to challenge healthcare systems around the world, technologies that accelerate the discovery and testing of new antibacterial compounds could become an increasingly important part of the global research effort.