An Integrated Photoelectrochemical Nanotool for Intracellular Drug Delivery and Evaluation of Treatment Effect

Abstract

With reduced background and high sensitivity, photoelectrochemistry (PEC) may be applied as an intracellular nanotool and open a new technological direction of single‐cell study. Nevertheless, the present palette of single‐cell tools lacks such a PEC‐oriented solution. Here a dual‐functional photocathodic single‐cell nanotool capable of direct electroosmotic intracellular drug delivery and evaluation of oxidative stress is devised by engineering a target‐specific organic molecule/NiO/Ni film at the tip of a nanopipette. Specifically, the organic molecule probe serves simultaneously as the biorecognition element and sensitizer to synergize with p‐type NiO. Upon intracellular delivery at picoliter level, the oxidative stress effect will cause structural change of the organic probe, switching its optical absorption and altering the cathodic response. This work has revealed the potential of PEC single‐cell nanotool and extended the boundary of current single‐cell electroanalysis.

A High Spatiotemporal Iontronic Single-Cell Viscometer

“…The practical applicability of the nanotool was then in vitro studied. Previous reports had revealed the potentialdirected delivery or sampling functions of nanopipettes [2,10,27,28], the function of which was initially investigated using HEPES milieu containing saturated fluorescein. As shown in Figure 2(a), such an effect was verified by 20 min electroosmosis under -1.0 V, which led to obvious green fluorescence of fluorescein within the nanotool.…”

“…2(e), the HEPES milieu of 60 cP containing 130 mM K + and different Na + concentrations of (i) 2.5 mM, (ii) 10 mM, and (iii) 15 mM were tested, and hardly any signal variation could be observed. Besides, to study the possible pH variation effect, as shown in Figure 2(f), HEPES milieu of 60 cP with pH of 6.6, 7.4, and 7.8 had almost no effect on the response of the nanotool [10,14]. To study the possible adsorption effect, the nanotool was sequentially immersed into the cell lysate for 10 min and then tested for three repeated times.…”

“…Nevertheless, to yield electrical signals, occurrence of Faradic reactions at specific potentials and wired circuits are the necessity, which severely restricts this methodology to redox-involved events. To take it a step further, scientists have endeavored to exploit new nanoelectrochemistry and mechanism [9][10][11][12]. For example, using a single nanopipette, confined electrochemiluminescence has recently been exploited for wireless intracellular analysis [9].…”

“…For example, using a single nanopipette, confined electrochemiluminescence has recently been exploited for wireless intracellular analysis [9]. Photoelectrochemistry of engineered organic molecules and semiconductor hybrid has been used for studying intracellular oxidative stress [10]. Utilization of the ionic current rectification could even realize the detection of intracellular H 2 O 2 [11] and microRNA [12].…”

Chemical Measurement and Analysis: from Phenomenon to Essence

“…Recently, we extended the boundary of current single‐cell electroanalysis by developing a photoelectrochemistry (PEC) nanotool. [ 117 ] At the tip of nanopipette, an organic molecule/NiO/Ni film was engineered, which served as both the biorecognition element and sensitizer to synergize with p‐type NiO. Upon intracellular delivery at picoliter level, the oxidative stress effect caused structural change of the organic probe, switching its optical absorption and altering the cathodic response caused by the photon‐to‐electricity conversion.…”