Wearable Biosensors for Stress Biochemical Markers

Wearable Biosensors for Stress Biochemical Markers

Wearable biosensors are a subclass of point‐of‐care devices that are designed to continuously monitor analytes in peripheral biofluids. In the realm of neuropsychiatry, stress biomarkers such as cortisol, inflammatory cytokines, and even certain metabolic indicators are of great interest. Traditionally, cortisol has been the most targeted biomarker because changes in its concentration reliably mirror fluctuations in psychological stress (Sheffield, Paul, Krishnakumar, & Pan, 2025). However, the inherent lack of specificity of cortisol to one particular neuropsychiatric disorder has steered researchers to develop multiplex wearable biosensors. These devices are designed to simultaneously capture several biochemical markers, thereby addressing the complexity and heterogeneity of neuropsychiatric illnesses.

Current sensor designs use a multitude of biorecognition elements including antibodies, molecularly imprinted polymers (MIPs), and aptamers, which allow for heightened selectivity and reusability in continuous monitoring conditions. For instance, antibody‐based immunosensors have been successfully integrated onto conductive substrates such as laser‐burned graphene or MXene flakes. In one design, competitive binding on an immunosensor enabled the quantification of cortisol in sweat by using cortisol conjugated to an enzyme reporter (Sheffield et al., 2025). Other studies have employed MIPs that are formed in the presence of cortisol so that once the template molecule is removed, a tailor‐made binding cavity is left behind. Both approaches show promise in filtering out non‐specific interference and enhancing overall sensor performance.

A major advantage of wearable biosensors is their potential for noninvasive, continuous monitoring. Sweat is currently the most explored biofluid for these devices due to the ease of collection and the minimal requirement for external stimulation. Soft microfluidic patches, which are integrated onto the skin, use capillary forces and hydrophilic treatments on channel surfaces to direct sweat flow to the sensing area. Researchers have designed innovative microfluidic networks that employ valves—such as check valves or bursting valves—to control the sample delivery sequence and thereby obtain a steady stream of fresh analyte for measurement.

Below is a sample table summarizing key parameters of selected wearable sweat biosensors targeting cortisol:

Table 1. Examples of wearable biosensor platforms for cortisol detection in sweat. All values are illustrative and adapted from recent studies (Sheffield et al., 2025).

The development of these systems involves challenges such as addressing biofouling, signal drift over prolonged periods, and interference from varying pH and ionic strength in sweat. Recent technological advances have focused on incorporating anti‐biofouling membranes (e.g., Nafion and cellulose acetate) and using stabilization techniques for the biorecognition components. Although most wearable devices have concentrated on cortisol, researchers advocate for multiplex systems that would also integrate markers such as dehydroepiandrosterone (DHEA), inflammatory cytokines, and certain metabolic indicators. This multi‐analyte approach is expected to offer richer diagnostic insight, enabling clinicians to distinguish between overlapping manifestations of neuropsychiatric illnesses.

Moreover, some groups have begun integrating optical detection methods into wearable systems. For example, lateral flow immunoassays embedded in microfluidic frameworks have been paired with smartphone-based reading systems that identify visible color changes corresponding to cortisol levels. Optical biosensing can reduce reliance on complex electronics and power requirements—though many optical assays still face challenges related to the need for reagent replenishment and device disposability.

Overall, wearable biosensors are paving the way for personalized healthcare by providing objective, continuous data about a patient’s stress status. These data-rich devices have the potential to complement traditional psychological assessments by providing quantifiable biochemical measurements that can inform both diagnosis and treatment selection for neuropsychiatric conditions (Sheffield et al., 2025).

Parental Mentalization and Child Mental Health

A parallel field that has drawn significant attention in recent years is parental mentalization. Mentalization is defined as the human capacity to understand one’s own and others’ mental states, including emotions, desires, intentions, and thoughts (Frith & Frith, 2003). In the context of parenting, this ability is often referred to as parental reflective functioning (PRF) or mind‐mindedness. It encapsulates a parent’s skill in perceiving their child as an individual with internal experiences that are separate from their own.

The theory behind mentalization evolved from earlier constructs such as theory of mind (Premack & Woodruff, 1978) and empathy (Gordon, 2003). Researchers have come to appreciate mentalization as a transtheoretical umbrella concept that organizes capacities into dimensions (cognitive versus affective, explicit versus implicit, self versus other) (Luyten & Fonagy, 2021). Empirical studies suggest that higher levels of parental reflective functioning are associated with improved socio‐emotional development in children. Secure attachment processes and sensitive parenting practices are undergirded by a parent’s ability to reflect on both their own emotional states and those of their child. Conversely, impaired mentalization in parents has been linked to a host of child behavioral problems—ranging from internalizing symptoms (such as anxiety and depression) to externalizing behaviors (such as aggression and hyperactivity) (Sharp & Fonagy, 2008).

Recent research underscores that parental mentalization acts as a protective factor for child mental health. A host of longitudinal studies have documented significant associations between improved parental mentalization scores—measured using instruments such as the Parental Reflective Functioning Questionnaire (PRFQ) and the Mind‐Mindedness Coding Manual—and enhanced child outcomes in domains such as emotion regulation, social competence, and even academic performance. For example, studies have reported that when mothers demonstrate high levels of mind‐mindedness, their children tend to show fewer behavioral difficulties and better internal regulation skills (Meins et al., 2013).

One area of investigation is how the quality of parental reflective functioning moderates the transgenerational transmission of psychopathology. A number of studies have shown that even in settings where parents experience elevated levels of psychological distress, higher reflective functioning may buffer children from developing similar symptoms. In some research, the interaction between parental sensitivity and adverse experiences has been shown to significantly predict child behavior problems, indicating that mentalization may mediate the negative impact of stress on family dynamics.

It is important to note that while many studies have focused on the mentalization of mothers, recent data suggest that fathers’ reflective capacities also play a crucial role in child development. Although fathers are less frequently studied than mothers, emerging evidence indicates that paternal mentalization may have unique moderating effects on dimensions such as externalizing behaviors and social functioning in children (Mora et al., 2023).

Below is a summary table highlighting some key findings from research on parental mentalization and child mental health:

Table 2. Selected empirical findings on the association between parental mentalization and child mental health outcomes. Data are adapted from multiple studies (Meins et al., 2013; Priel et al., 2000; Walker & Cheng, 2007; Mora et al., 2023).

In addition to reducing the risk of psychological symptoms, promoting parental mentalization might also lead to an increase in positive outcomes such as resilience, academic competence, and overall well‐being. Integrating mentalization training into early intervention programs may provide new avenues for preventive mental health practices.

Integrating Technology and Parental Practices to Enhance Child Mental Health

The emerging overlap between technological advances in wearable biosensors and the evolving understanding of parental mentalization creates an unprecedented opportunity in the field of child mental health. On one side, wearable sensors can provide objective, continuous feedback about a parent’s physiological stress response. On the other, reducing parental stress and promoting reflective capacities is crucial to foster a nurturing environment for children.

For example, should a parent be aware that their stress levels are elevated—as measured by a wearable device monitoring sweat cortisol and related biomarkers—they may be prompted to engage in relaxation techniques and reflective practices. Such mindfulness may improve their capacity to mentalize when interacting with their child. The use of multiplex wearable biosensors not only serves as a tool for clinical diagnosis of neuropsychiatric conditions but can also be integrated into behavioral intervention programs.

One can envision a future where personalized digital health platforms combine data from wearable biosensors with interactive parental coaching applications. Parents could receive real-time updates regarding their stress levels, along with tailored suggestions for stress reduction and reflective exercises. In turn, enhanced parental mentalization would promote secure attachment and resilience in children, thereby reducing the intergenerational transmission of mental health vulnerabilities.

The integration of these advances in clinical practice requires multidisciplinary collaboration. Engineers, clinical psychologists, pediatricians, and public health professionals must work together to refine wearable biosensor technologies, validate novel biomarkers, and design effective mentalization–based intervention protocols. Government agencies and policy-makers can play a significant role by funding research that bridges these domains, providing support for early public health interventions that emphasize both technological innovation and improved parenting practices.

Future Directions and Implications

The rapid progress in wearable biosensor technologies is set to revolutionize how we monitor and manage mental health. For neuropsychiatric applications, the continued evolution of multiplex detection—where a single wearable device simultaneously monitors a range of stress‐related biomarkers—promises more refined diagnostic capabilities. More work is needed to standardize sensor designs, enhance long-term sensor stability under variable environmental conditions, and improve integration with other digital health tools.

Similarly, research in parental mentalization is growing. Future studies should pay closer attention to the contributions of both mothers and fathers, while also capturing the nuances of cultural and socio-economic diversity. Further investigations are necessary to disentangle the methods by which different dimensions of parental mentalization (e.g., appropriate mind‐mindedness versus overmentalizing) either promote resilience or, in some cases, paradoxically contribute to stress in children.

The implications for mental health policy are profound. Interventions that focus on strengthening parents’ reflective capacities are likely to have long-lasting effects not only on child functioning but also on the overall well-being of families. As highlighted by global leaders such as Henrietta H. Fore (2019), early intervention is critical given that half of mental disorders begin before the age of 14. Investing in programs that enhance both wearable biosensor technologies and parental mentalization may ultimately reduce the societal burden associated with neuropsychiatric conditions.

Frequently Asked Questions (FAQ)

What are wearable biosensors and how are they used to monitor stress?
Wearable biosensors are small, noninvasive devices that continuously monitor biomarkers in peripheral biofluids such as sweat, saliva, or tears. They employ biorecognition elements (like antibodies or aptamers) to detect analytes such as cortisol, which is closely linked to stress. These sensors can transmit data in real time, thereby aiding in the diagnosis and management of neuropsychiatric conditions (Sheffield et al., 2025).

What is parental mentalization?
Parental mentalization refers to a parent’s ability to understand both their own mental states and those of their child. This capacity, often measured by tools such as the Parental Reflective Functioning Questionnaire (PRFQ), plays a pivotal role in forming secure attachment and fostering healthy socio‐emotional development in children (Frith & Frith, 2003; Luyten & Fonagy, 2021).

How do wearable biosensors and parental mentalization interact to benefit child mental health?
Wearable biosensors provide objective data on parental stress by monitoring biomarkers like cortisol. When parents are made aware of elevated stress levels, they can take steps to reduce stress and engage in reflective practices. Improved parental mentalization, in turn, supports better child outcomes by helping create a nurturing and responsive environment (Sheffield et al., 2025; Meins et al., 2013).

Can the information from wearable biosensors be used in clinical practice?
Yes, the data from wearable biosensors can complement traditional psychiatric assessments by providing continuous monitoring of stress biomarkers. When integrated with digital health platforms, such data can support early diagnosis and tailor intervention strategies for individuals at risk for neuropsychiatric ailments (Sheffield et al., 2025).

What future advancements are expected in these fields?
Advances in sensor technology will likely lead to more robust multiplex devices that detect several stress‐related biomarkers simultaneously, thus allowing for enhanced diagnostic specificity. In parallel, research on parental mentalization is expected to broaden its scope to include diverse populations and both maternal and paternal roles, ultimately influencing preventive mental health policies (Luyten & Fonagy, 2021; Mora et al., 2023).

References

1. Sheffield, Z., Paul, P., Krishnakumar, S., & Pan, D. (2025). Current Strategies and Future Directions of Wearable Biosensors for Measuring Stress Biochemical Markers for Neuropsychiatric Applications. Advanced Science, 12, 2411339. https://pubmed.ncbi.nlm.nih.gov/11791988/

2. [Pica in childhood: Prevalence and developmental comorbidity]. (2023). Frontiers in Child Health and Allied Sciences. https://doi.org/10.3389/frcha.2023.1099527

3. Unsal, S., & Sanlier, N. (2025). Longitudinal Effects of Lifetime Caffeine Consumption on Levels of Depression, Anxiety, and Stress: A Comprehensive Review. Current Nutrition Reports, 16(5). https://doi.org/10.1007/s13668-025-00616-5

4. Frith, U., & Frith, C. (2003). Development and neurophysiology of mentalizing. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 358, 459–473

5. Luyten, P., & Fonagy, P. (2021). Integrating and differentiating personality and psychopathology: A psychodynamic perspective. Journal of Personality, 90, 75–88

6. Meins, E., Centifanti, L. C. M., Fernyhough, C., & Fishburn, S. (2013). Maternal mind‐mindedness and children’s behavioral difficulties: Mitigating the impact of low socioeconomic status. Journal of Abnormal Child Psychology, 41(4), 543–553

7. Mora, S. C., Bastianoni, C., Pederzolli, M., Rospo, F., & Bizzi, F. (2023). Which space for fathers’ mentalizing? A systematic review on paternal reflective functioning, mind‐mindedness and insightfulness. Journal of Child and Family Studies, 32(5), 1261–1279. https://doi.org/10.1007/s10826-023-02559-3

8. Walker, L., & Cheng, S. (2007). What enhances the development of emotion understanding in young children? A longitudinal study of interpersonal predictors. British Journal of Developmental Psychology, 25, 221–232

9. Henrietta H. Fore, UNICEF Executive Director (2019). Quote on the importance of child mental health promotion and disease prevention

10. Premack, D., & Woodruff, G. (1978). Does the chimpanzee have a theory of mind? Behavioral and Brain Sciences, 1(4), 515–526. https://doi.org/10.1017/s0140525x00076512

11. Sharp, C., & Fonagy, P. (2008). The importance of mentalizing in clinical practice. Attachment & Human Development, 10(4), 439–463

12. Additional references for parental mentalization and child mental health concepts are available in the literature; please refer to comprehensive reviews such as Luyten et al. (2020).

FAQ

What are wearable biosensors and why are they important for neuropsychiatric applications?
Wearable biosensors are devices designed to monitor biomarkers continuously via noninvasive access to biofluids like sweat. They are important in neuropsychiatric contexts because they provide objective measurements of stress levels (e.g., cortisol) which can inform both diagnosis and therapeutic interventions (Sheffield et al., 2025).

How does parental mentalization affect child mental health?
Parental mentalization is the parent’s capacity to understand their own and their child’s internal states. High levels are linked to increased attachment security, improved emotion regulation in children, and lower levels of behavioral problems (Meins et al., 2013; Walker & Cheng, 2007).

Can these innovative technologies be integrated into everyday parenting practices?
Yes, by combining wearable biosensor data—such as real-time stress indicators—with targeted mentalization training and reflective parenting strategies, parents can better regulate their own stress responses and improve parent–child interactions, leading to more positive child outcomes.

What challenges remain in bringing these technologies and concepts into clinical practice?
Several challenges include ensuring long-term biosensor stability, developing standardized multiplex systems for several biomarkers, addressing individual variability in sweat composition, and expanding research on parental mentalization to involve fathers and diverse cultural settings.

What future developments can we expect in these fields?
Future developments are likely to include more advanced, multiplexed wearable biosensors that monitor a broader range of stress biomarkers. In parallel, enhanced training programs for parents focusing on reflective functioning and mentalization may be developed, possibly integrated with digital health platforms for a holistic approach to child mental health.

Feel free to share your thoughts and questions in the comments below, and join the discussion on how technology and parenting practices can collaboratively enhance child mental health.