Detecting cancer cells and parasites

Scientists in Denmark have designed a new sensor to detect cells that over-express folate receptors, including cancer cells. Jaime Castillo-León from the Technical University of Denmark and colleagues' sensor consists of an electrochemical platform composed of graphene and peptide nanotubes with folic acid.

Cancer cells have a high requirement for folic acid as it is necessary for their metabolism, so the cells have 500 times more folate receptors compared with a healthy cell, explains Castillo-León. The receptors are like antennas on the surface of the cell membrane that seek out folic acid. The cancer cells interact with the electrochemical platform, resulting in a decrease in the current being measured. The sensor allows the detection of cancer cells at a concentration as low as 250 cells per millilitre.

Nanotube-folic acid modified graphene electrode

The nanotube–folic acid modified graphene electrode; the interaction between folic acid and folate receptors on HeLa cells

The sensor can also be used to detect other types of cells that over-express folate, says Castillo-León, such as cells infected with the parasites responsible for leishmaniasis (a tropical disease that affects millions of people in undeveloped countries, but is listed as a neglected disease). ‘Despite being a tropical disease, leishmaniasis has appeared in Europe recently because of the importation of infected animals. Our sensor could be used by the authorities to identify infected animals before they are imported,’ he says.

Castillo-León adds that the biosensing platform used for this sensor could be expanded to an array of sensors able to evaluate several samples at the same time. This means it could be used for the high-throughput screening of potential anti-cancer medicines, by evaluating their effect on cancer cells. ‘Thousands of compounds could be evaluated in a rapid way,’ he says. ‘The simplicity of our electrochemical sensing platform makes it feasible to miniaturise it for the development of a point-of-care device, facilitating its use in non-clinical environments.’

‘Folic receptor detection based on this technique is sensitive, simple, fast and convenient,’ says Yuehe Lin from Pacific Northwest National Laboratory, Richland, US, who is an expert in biomedical diagnosis. ‘For the detection of real samples such as blood, urine and saliva, the nonspecific binding could be a problem that the authors need to investigate.’ He concludes that the work has good potential for future applications in the early stage diagnoses of diseases in which cells over-express folate receptors, and that the technique could be developed to detect other biomarkers.

Related Content

A new system for cancer detection

11 February 2013 Research

news image

A simple drug-based detector could speed up the clinical diagnosis of all kinds of cancer

Targeting breast cancer

28 March 2014 Premium contentFeature

news image

Tamoxifen has been treating breast cancer for 40 years, but few would have predicted how much this drug would contribute to s...

Most Read

Antimicrobial resistance will kill 300 million by 2050 without action

16 December 2014 News and Analysis

news image

UK report says resistance will cost global economy $100 trillion

Cutting edge chemistry in 2014

10 December 2014 Research

news image

We take a look back at the year's most interesting chemical science stories

Most Commented

A bad business

19 December 2014 Critical Point

news image

Targets and assessments can boost productivity at universities – but only if they do not stifle creativity and alienate the...

Chemistry behind the ‘blue man’ unlocked

1 November 2012 Research

news image

Biochemical model suggests that silver ions, not nanoparticles, cause a rare skin complaint