AP da Silva: From Sri Lanka to Global Molecule-Based Diagnostics, a Portrait of Serendipity in Science

AP da Silva, a pioneer in photochemistry and molecular computing, explains how a chance encounter with an encyclopaedia and a mentor sparked a career transforming medicine. From early curiosity in Sri Lanka to Belfast, he developed fluorescent molecular sensors that detect ions like sodium in tiny, biocompatible chips. His PET-based approach underpins portable blood analyzers now used worldwide, shortening a day-long lab wait to under a minute. Roche later helped scale the device, merging chemistry with computer-like logic gates to interpret signals. The discussion covers serendipity, the chemistry of sensors, and the big-picture potential of molecular computing in cancer surgery and beyond.

Introduction: A life in molecules

The Life Scientific episode opens with a portrait of Amilra Prasana da Silva, known as AP da Silva, a Sri Lankan-born chemist whose work sits at the intersection of photochemistry, biosensing, and molecular computation. He frames his career as a sequence of fortunate, humanity-driven moments and kindness from others which guided scientific discovery.

Origins and mentors: From a poor Colombo upbringing to science’s door

Growing up without electricity or running water, AP was shaped by his mother’s determination and a pivotal teacher, Errol Fernando, who taught him that chemistry reveals how matter transforms and connects to the world around us. A single, water-damaged Encyclopaedia Britannica volume changed his trajectory, igniting a lifelong fascination with invention and technology. "Serendip is an old name for Sri Lanka, which translates as golden island in the Indian epics" becomes a running theme in his narrative of luck and learning.

Education and early research: Photochemistry and persistence

AP moves to study chemistry at Columbia University and then Belfast, where he pursued organic photochemistry. His early work on persistent pollutants and their interaction with light laid the groundwork for his future development of sensors that react to light to reveal chemical information in living contexts. He describes how measuring faint light emissions from molecules can illuminate their environment, a concept at the heart of fluorescence sensing.

The PET sensor idea: Molecular logic for sodium detection

The core of AP’s breakthrough is the use of photo-induced electron transfer, or PET, to build a light-emitting sensor that reports on ion concentrations. He explains the modular assembly: a fluorescent dye and a receptor designed to receive a specific ion. When the target ion, such as sodium, is absent, the dye emits no light because energy is siphoned off; when present, the transfer is blocked and fluorescence turns on. The metaphor of an arranged marriage captures how two well-understood components are joined to yield a new emergent function. "it's like arranging a marriage between two components whose properties are well understood" - AP da Silva

From bench to bedside: A turning point with Roche

The narrative reaches a pivotal moment when Roche approaches Belfast during a time of conflict, seeking a portable, rapid blood analyzer capable of measuring sodium, potassium, and calcium in minutes. AP describes the integration of six fluorescent PET sensors into a small chip in a disposable cartridge, enabling near-instantaneous results at the point of care and transforming critical care decisions.

The merger of chemistry and computing: A vision beyond silicon

AP draws a parallel between molecular sensors and computer logic, arguing that chemistry offers a biocompatible substrate for information processing at scales that silicon cannot access inside the body. He envisions networks of molecular logic gates that can detect combinations of signals within cells, guiding applications from tumor delineation to diagnostics. The discussion highlights how chemistry and computer science can inform each other in the design of robust, miniaturized sensing systems.

Applications and future directions: Surgery, diagnostics, and serendipity

The conversation covers fluorescence-guided tumor surgery and the potential to define tumor boundaries more precisely by leveraging multiple molecular inputs. AP emphasizes that the field thrives on serendipity, kindness, and cross-disciplinary collaboration. He closes with reflections on retirement, ongoing lab work, and the durability of ideas that outlive their originators.

Award, reflection, and legacy

AP recalls receiving the Royal Society of Chemistry blue plaque, praising the unexpected honor of being recognized while still alive. He also notes how mentoring and new generations will carry his ideas forward, ensuring the sensor concepts continue to influence science and medicine. A closing sense is one of gratitude for serendipity and for the people who enabled him to translate chemistry into life-saving technologies.

"Serendip is an old name for Sri Lanka, which translates as golden island in the Indian epics" - AP da Silva

"it's like arranging a marriage between two components whose properties are well understood" - AP da Silva

"Opposites attract" - AP da Silva

"Blue plaques are normally given to dead people" - AP da Silva