A team of scientists at the National Institute of Technology (NIT), Calicut has developed eight innovative sensor designs and a highly sensitive, low-cost, portable device capable of detecting endotoxins quickly and accurately. This technology has the potential to be used right at a patient’s bedside for early diagnosis.
Seven of these sensors were developed by Dr. N. Sandhyarani, Professor at NIT Calicut, and her team using electrochemical detection, while one sensor uses optical detection. To achieve high sensitivity, they integrated specially modified nanomaterials such as gold atomic clusters or nanoparticles, CuO or copper nanoclusters, MoS₂, reduced graphene oxide, and carbon nanotubes (CNTs).
Their work, published in the journal Langmuir, highlights a highly sensitive electrochemical sensor chip designed to selectively detect lipopolysaccharide (LPS)-a key marker of endotoxins. This chip, made with functionalized CNTs (fCNT) and copper(I) oxide nanoparticles (Cu₂O), works with a portable analyzer for on-site testing.
To ensure accurate results, the sensor uses LPS‑binding aptamers or polymyxin B for specific endotoxin binding, giving it excellent selectivity even in the presence of other interfering substances. The team successfully detected endotoxins in biphasic isophane insulin (a pharmaceutical drug), fruit juices, and whole blood using a standard addition method, achieving recovery rates with less than 2% error.
Two of the electrochemical platforms also proved capable of detecting Gram‑negative bacteria such as E. coli in water samples. Their performance matched traditional biological methods while cutting down testing time, showing great potential for rapid water quality monitoring.
Building on these sensor surfaces, the team went further to create a point‑of‑care device. They designed, built, and tested a portable, affordable electrochemical biosensor prototype that can detect endotoxins in blood serum. Remarkably, this device delivers results in under 10 minutes, paving the way for quick bedside diagnosis of conditions like sepsis.
