The device is the work of Sina Khazaee Nejad, Maral Mousavi, and colleagues, who set out to merge two functions that are normally separated in diagnostic testing: sample collection and analysis. Traditional saliva testing typically involves a swab or absorbent pad that soaks up fluid from the mouth, after which the sample must be packaged, transported, and processed on benchtop instruments elsewhere. That separation adds time, cost, and opportunities for error, and it can be particularly awkward when the patient is a child. By contrast, Lollylab is designed to do everything at once. The candy coating stimulates saliva production, the stem channels the fluid to an integrated sensor, and the sensor reports the result on the spot. As Nejad, the first author of the paper, explained, turning a familiar object like a lollipop into both a collection device and a sensor means the sample can be gathered and measured directly at the point of care.

The clinical motivation behind the project is rooted in the pharmacology of acetaminophen itself. The compound, known in some countries as paracetamol, is an ingredient in a vast array of over-the-counter products, including standalone pain relievers and combination cold and flu remedies. Because it is so easy to obtain and appears in so many formulations, unintentional overdose is a persistent safety concern. Taking more than the maximum recommended dose can cause serious side effects, most notably liver damage. The risk is especially acute for children, who can experience harm at lower levels of the medication than adults and who may be exposed accidentally when caregivers underestimate how much of the drug is already present in combination products. A quick, noninvasive way to check how much of the drug is circulating in a patient’s body could therefore be a meaningful safeguard.

Saliva turns out to be a surprisingly good window into that circulating level. Previous work has shown that acetaminophen concentrations in saliva closely reflect those in blood, which means the drug’s pharmacokinetics can be tracked without drawing blood. That correlation is what made the researchers consider saliva as a simple, noninvasive monitoring medium. The challenge was not so much detecting the drug in saliva as making the entire process pleasant enough that patients, and especially young ones, would cooperate willingly. Blood draws are invasive and frightening for many children, and even standard saliva swabs can trigger gagging or discomfort. The insight behind Lollylab is that the collection step could be reframed as a treat rather than a procedure.

The design lineage of the device traces back to an earlier invention called CandyCollect, a lollipop-like sampling system developed to replace throat swabs for diagnostic testing. Mousavi says that system inspired the team, but CandyCollect specimens still need to be analyzed elsewhere, so the researchers wanted to go a step further and create what they describe as a miniature laboratory-on-a-lollipop. Where CandyCollect demonstrated that a candy-based device could harvest useful biological samples at home, Lollylab embeds the analytical chemistry into the lollipop itself, closing the loop between collection and measurement.

Mechanically, the device is elegantly simple. It is built from two plastic pieces, each with a round end and a thinner stem, that snap together. Holes at the top allow saliva to enter the interior of the candy head. The upper portion of the device is coated with a red, peach-flavored edible candy shell, which serves a dual purpose: it makes the object genuinely appealing to lick, and the act of licking stimulates the flow of saliva that the test requires. Importantly, the researchers confirmed that the candy coating did not interfere with the measurements, so the flavoring is a genuine functional element rather than a cosmetic afterthought.

Once saliva enters the device, it flows through the lollipop’s stem, which is lined with glass fiber paper, toward a sensor at the bottom. That sensor is made of graphene, a single-atom-thick form of carbon prized in electrochemical sensing for its high conductivity and large surface area. The graphene electrode measures acetaminophen levels as changes in electrical current, a readout strategy common in electroanalysis: the drug oxidizes at the electrode surface, and the magnitude of the resulting current is proportional to its concentration in the sample. Because the electronics can be miniaturized, the entire analytical pathway fits within the stem of a lollipop-sized object. In laboratory testing, the prototype successfully detected acetaminophen in both artificial saliva and real human saliva, demonstrating that the candy matrix and the complex chemistry of real oral fluid did not block the electrochemical signal.

The proof-of-concept study put the device into the hands of actual users. Six adults used Lollylab before taking a standard adult dose of acetaminophen, 650 milligrams, and then again an hour after taking it, a timeframe chosen to capture the period when the drug reaches measurable levels in the body. The device reliably measured the drug in the participants’ saliva in less than two minutes, confirming that the sampling-to-signal pipeline works on realistic post-dose saliva rather than only on spiked laboratory samples. Just as significant for the researchers, the participants said the device was easy to use and more comfortable than typical saliva swabs, an early signal that the candy-based format may overcome the compliance problems that plague conventional oral fluid collection.

For Nejad, the central message of the work is that diagnostic testing can be made much easier and more comfortable, especially for children. That framing positions Lollylab not merely as a faster acetaminophen meter but as a template for a different philosophy of diagnostics, one in which the sample collection experience is designed around the patient rather than the laboratory. A device that a child is happy to put in their mouth removes a major barrier to repeated testing, which matters for monitoring because a single measurement captures only one moment in the drug’s journey through the body. Repeated, low-friction measurements could give clinicians a fuller picture of how a patient is absorbing and clearing a medication.

The team’s roadmap extends well beyond acetaminophen. Next, the researchers plan to validate Lollylab’s acetaminophen measurements with more participants, including children, the population for whom the device’s comfort advantages matter most. They also intend to develop the platform to detect other substances in saliva, such as naturally occurring stress markers, and their longer-term goal, as Nejad describes it, is to create a multi-assay platform capable of measuring several biomarkers, which could then be evaluated alongside acetaminophen in larger clinical studies. The work was funded in part by a 3M Nontenured Faculty Award, Women in Science and Engineering at the University of Southern California, and the President’s Sustainability Research Award, and some of the authors have filed a provisional patent based on the device. If subsequent validation succeeds, the humble lollipop may become a serious instrument of point-of-care medicine, transforming a routine dose check from a clinical chore into something a patient might actually look forward to.

Subject of Research: A lollipop-shaped saliva collection and graphene electrochemical sensing device for point-of-care monitoring of acetaminophen levels

Article Title: Candy-coated Lollylab checks saliva for medication

Article References: Candy-coated Lollylab checks saliva for medication. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Lollylab, acetaminophen, saliva diagnostics, graphene sensor, point-of-care testing, pediatric safety, drug monitoring, electrochemical sensing, CandyCollect, ACS Sensors, noninvasive testing, biomarkers

Electrochemical aptamer-based, or EAB, sensors work by tethering a redox-labeled aptamer, a short single-stranded nucleic acid folded to bind a specific target, to an electrode. When the target molecule binds, the aptamer changes shape, altering the distance between the redox reporter, typically methylene blue, and the electrode surface. That distance change modulates electron transfer, producing a measurable current shift without any reagents or labels. Because the binding is reversible, the same sensor can be interrogated repeatedly, making the platform uniquely suited to real-time tracking in living bodies. The concept dates to work by Fan, Plaxco and Heeger in 2003, and the field has since demonstrated sensors for chemotherapeutics, antibiotics, cocaine, glucose, lactate, phenylalanine and inflammatory cytokines.

The pharmacological applications are the most mature. A landmark system called MEDIC tracked the chemotherapy drug doxorubicin in whole human blood for over four hours with deviations below 0.06 micromolar, then reproduced the feat in live rats, keeping drift below two percent through a signal-processing trick known as kinetic differential measurement. Later work extended the approach to awake, freely moving animals, achieving second-scale pharmacokinetic measurements of antibiotics. More recently, flexible nanoporous gold electrode arrays implanted into melanoma tumors in mice revealed striking differences between drug concentrations in plasma and in tumor tissue, a disparity that conventional blood sampling simply cannot see. In the brain, aptamer-functionalized probes have resolved cocaine dynamics with sub-five-second temporal resolution.

But the review, which synthesizes progress across chemistry, materials science and electronics, is candid about the central obstacle: most EAB sensors survive only hours in the body, not the weeks or months that clinical deployment would demand. The degradation is multifactorial. Repeated voltammetric scanning itself damages the sensor, because potentials more negative than about minus 0.2 volts drive oxygen reduction and generate locally destructive hydrogen peroxide, while potentials above plus 0.2 volts oxidize the gold electrode. Studies using scanning electrochemical microscopy measured peroxide concentrations reaching 320 micromolar near the surface, enough to corrode the self-assembled monolayer that anchors the aptamers.

Even without electrical stress, the sensors fall apart. The gold-sulfur bonds holding the molecular layer degrade thermally at body temperature, with defect-rich regions of the monolayer acting as initiation sites for detachment. At 37 degrees Celsius in serum, conventional mercaptohexanol-based sensors lost their signal within three days, while identical sensors held at 4 degrees Celsius remained robust for at least a week. Endogenous thiols such as cysteine and glutathione compound the problem by chemically displacing the gold-bound molecules, and adsorbing serum proteins restrict the aptamer’s freedom to fold, blunting the signal. Notably, nuclease digestion, long suspected as the primary culprit, turns out to be context-dependent: in vitro, nuclease-resistant mirror-image DNA degraded at nearly the same rate as natural DNA, suggesting fouling and monolayer loss dominate early signal decay, whereas in vivo experiments show enzymatic cleavage becomes significant once interfacial degradation is controlled.

The most compelling recent advance comes from xenonucleic acids, synthetic nucleic acid analogues whose modified backbones evade nuclease recognition. When researchers replaced DNA aptamers with 2′-O-methyl RNA, sensors implanted in rat jugular veins lost only about seven percent of their signal over five hours, compared with roughly forty-eight percent for DNA-based controls, a sevenfold reduction in drift. Building on that foundation, a separate team achieved continuous, seconds-resolved drug measurements over a full week in vivo, tracking circulating tobramycin across multiple dosing events without any protective coating or nanoengineered electrode. After seven days, the sensor still retained about forty percent of its initial current with well-defined voltammetric peaks.

Materials strategies are advancing in parallel. Hydrogel coatings form hydrated barriers that exclude cells and proteins while allowing small molecules to diffuse through; a combinatorially screened polyacrylamide hydrogel kept implanted sensors responsive with only about twenty-four percent signal loss after five days in rat veins. Zwitterionic polymers, whose balanced positive and negative charges bind water exceptionally tightly, resist protein adsorption and have been shown in mice to prevent fibrotic capsule formation for months. Nanostructured electrodes add another layer of protection: nanoporous gold physically shelters aptamers inside nanocavities too small for proteins and nucleases to enter, and when combined with a hyperbranched polyethylene glycol coating, such sensors retained over seventy percent of their signal after twenty-eight days in human serum and remained functional after a week implanted in freely moving rats.

System integration is also maturing rapidly. Application-specific integrated circuits such as the Analog Devices AD5940 now provide miniaturized, low-noise electrochemical front ends, while Bluetooth Low Energy microcontrollers handle wireless data transmission. Fully integrated platforms have been demonstrated across nearly every form factor: a skin-mounted wearable patch that measures the hormone estradiol in induced sweat with a detection limit of 0.14 picomolar, a microneedle array for interstitial fluid metabolites, a battery-free implantable catecholamine sensor, and an ingestible capsule that monitored serotonin, glucose and pH in the gut for over twenty hours. Most strikingly, a first-in-human pilot study reported a wearable EAB patch for continuous vancomycin monitoring in dermal interstitial fluid, delivering five-minute-resolved measurements for more than a day, though signal degradation limited the highest-quality data to the first twelve hours.

An emerging frontier is bioresorbability, the idea that sensors should safely dissolve after their useful life rather than require surgical retrieval. Printed electrochemical glucose monitors built from zinc, molybdenum and tungsten pastes on biodegradable polymer substrates have been shown to disappear completely within eight weeks in rats, leaving no residue or inflammation. A newly reported programmable system goes further, using an electronic suture to connect a bioresorbable microneedle implant to external electronics, with an applied electrical trigger commanding when the implant begins to degrade, enabling multimodal monitoring of deep-organ physiology without permanent hardware.

The review’s authors distill the remaining challenges into a clear agenda: extending operational lifetimes from days to months, quantitatively deciphering how degradation mechanisms interact in vivo, combining stabilization strategies that have so far been deployed in isolation, building fully integrated and eventually fully bioresorbable devices, and pushing the platform toward difficult targets such as low-abundance proteins, whose slow diffusion and tight binding kinetics complicate reversible sensing. If those hurdles fall, the payoff could be transformative: continuous troponin monitoring for earlier heart attack detection, real-time chemotherapy dosing guided by tumor microenvironments, and round-the-clock cytokine tracking for autoimmune disease. The field has proven that aptamer sensors can see molecules no enzyme-based monitor can. The task now is to make them last long enough to matter.

Subject of Research: Electrochemical aptamer-based sensors for long-term in vivo continuous molecular monitoring

Article Title: Continuous Molecular Monitoring Using Electrochemical Aptamer‐Based Sensors: Remaining Challenges for Long‐Term In Vivo Deployment

Article References: Liu, S., Li, X., & Ouyang, W. (2026). Continuous Molecular Monitoring Using Electrochemical Aptamer‐Based Sensors: Remaining Challenges for Long‐Term In Vivo Deployment. Advanced Science, Article e77896. https://doi.org/10.1002/advs.77896

Image Credits: AI Generated

DOI: 10.1002/advs.77896

Keywords: aptamers, electrochemical biosensors, continuous monitoring, xenonucleic acids, biofouling, drug monitoring, wearable sensors, implantable devices, bioresorbable electronics, nanoporous gold, zwitterionic coatings, precision medicine