Ultrasensitive and real-time detection of proteins in blood using a potentiometric carbon-nanotube aptasensor

► Selective, ultrasensitive, economic and real-time detection in one step of proteins in real samples. ► Detection of 4 femtomols l−1 in buffered samples or 10 picomols l−1 in blood. ► Detection in blood is possible using a new working buffer tailored to be used in clinical samples.