Early detection of drugs on the spot is essential to reduce the impacts of the drug crisis

One of the key tools in tackling this addiction epidemic is drug detection among users, the researchers said. The classic laboratory method of monitoring the presence of drugs in the blood or urine of patients, which ranges from simple color chemical tests such as thin-layer chromatography to more complex methods such as gas chromatography and mass spectrometry, is reliable and precise. However, they do require samples to be sent offsite, which is a time consuming and expensive process. A quick, less expensive, and more consistent method of monitoring possible drug use could alert practitioners before their patients overdose.

“If the scan is very expensive, you’re going to limit how often you do the scan,” Rotkin said. “It has to be cheap, efficient and simple. As simple as possible because you have to take the blood sample from the patient, then you have to clean the blood, prepare the samples and take an hour’s time from a patient. specialist in a remote lab. It can cost a lot of money and so you won’t go for a regular scan unless it is very, very necessary But for addiction you should do it more frequently, just because the problem is so acute.

In the review article, the international team of researchers, including Rotkin, listed 203 references to a large number of research articles that indicate that biosensors have great potential to address these challenges. Biosensors could potentially solve this problem by providing high sensitivity, low cost analysis of a patient on an ongoing basis. A biosensor device includes a small sensor that is exposed to biological material and produces a chemical, optical, or electrical signal in response to a biostimulus. The design of these biosensors has evolved dramatically over the past two decades and appeared on the market in the form of over-the-counter glucose sensors for diabetic patients and home pregnancy tests. However, for the type of sensors needed for drug detection, Rotkin and his co-authors note that there is one problem: size.

“Based on what we currently have in biosensors, we’re like the early 1990s with cellphones,” Rotkin said. “We were using these huge cell phones which would be about the size of a regular landline at the time. , and you needed a bag to carry it.

The use of nanomaterials is promising and could potentially enable a biosensor for the detection of opiates and cocaine that would be small enough to be included in a dressing. Nanomaterials would provide a platform for bioreceptors and provide a “nanoarchitecture” on which to build highly sensitive, fast and small sensing devices.

The review article proposed aptamer-based sensors for drug detection. Aptamers are short sequences of RNA, DNA, or peptides. Aptamer molecules can be designed specifically as recognition elements for biosensors. Properties such as very small size, fast and inexpensive production process, biocompatibility and high stability make them ideal for such a biosensor.

“In the document, we described all of the existing technologies and weighed the pros and cons,” Rotkin said. “This includes the large number of sensors that currently exist based on electrochemical detection, which are extremely simple and inexpensive. But because of its ruggedness, which means it can detect everything, then the question is whether you can be selective and make it focus specifically on what you want to detect. Here the aptamers, which are designed to be selective, must help. ”

Other technologies they looked at included optical sensing, which works on the basis of the alteration of optical properties by a stimulus that generates a signal proportional to a substance’s concentration or its optical “fingerprints.” . Rotkin is collaborating with researchers at the University of North Carolina-Greensboro on such devices using heterostructures of 2D materials.

The additional sensors they examined included microfluidic sensors, which only require a small volume of samples for analysis; piezoelectric sensors, which respond to the applied mechanical stresses; and electromechanical sensors, which appeal to researchers because they are flexible and can detect compounds and particles of microscopic size.

The authors of the review article concluded that the main hurdles to overcome in creating such small and portable portable biosensors for drug addicted patients include the need to improve the reproducibility of biosensors, especially when analyzing media. ‘complex samples, and the ability to produce a sensor that does not require sample pretreatment to analyze them. In addition, the authors concluded that additional funding is needed to develop marketable biosensors at low cost and the correct analytical parameters.

“You need the right amount of funding to make this marketable biosensor happen,” Rotkin said. “And that’s always a challenge. So my fellow authors and I hope that maybe when people see this review, it will allow them, in a paper, to see what people have done. be that they can follow one of the kinds of sensors they’re looking for and go forward until we get the real product. ”